Search Engine Optimization Tips

Well here's the big problem with that: yes, I can just handle it and send you a report each month and I have clients where that works very well. But every single one of those clients has someone else handling all the "other" stuff that I'd be doing or thinking about, or they're knowledgeable themselves.
Link building can exist in a bubble and it can be successful that way, but it can't reach maximum success without the client getting involved on some level, and I'm talking about doing more than paying the invoices.
While we're on the subject of invoices and money, that's another problem: paying someone to do link building for you can get very expensive, especially if they're really good at what they do. For some small business owners, the cost is difficult to justify so they have to either do it themselves or accept the fact that they probably won't be able to compete very effectively.
The beauty of building links is that there are many, many things that can be done to both get you a link and raise your visibility so that your likelihood of generating more links increases. You can get a link from:

Handing out your business card.
Talking to your neighbor who mentions your business to the barista who makes his morning latte and is overheard asking another customer if he knows of anyone in town who does what you do because he wants to interview them for his side project, a personal blog.
Emailing someone and asking for it.
Someone who finds your content in a search.

You can also invest some time in making your site a better and more efficient resource for your users. Link building isn't just about doing something that immediately gives you a text link. Links can be built from 100 different paths, some of which you'll never be able to accurately track.
It's hard to get that idea across to many clients who want to get lots of links and get them right now.
You have no idea how many times I've gone to a client and said "you know, if we rewrote the content on this page a bit so that it better reflected the anchor you want us to use, I think we'd be better off" or "you might want to figure out where the contact us form goes because when I tested it, it went nowhere and no one got in touch with me" and they basically (and usually nicely) tell me to keep quiet and just build them some links.
You also have no idea of the times we've lost link opportunities when a webmaster said "I can't even get their site to load" or asked why we wanted specific anchor text when it made no sense.
For example, if I'm writing a post like this one and I need to cite a source about a topic, I'm not going to use a site that takes a full minute to load. I'm not going to use one where there are 50 spam comments with no legitimate ones. I have my personal biases as does everyone else, and if those biases mean that a site loses a link opportunity, then it's something that could be fixed in order to improve the odds of a link opportunity.
Let's go through a few quick things that any client can do on his or her own, just to get started on the path of (eventually or immediately) building links and improving the linkability of the site.
You probably won't see massive changes overnight with any of these ideas, but they're all practices that we conduct ourselves and advise clients to do. They're also quick and easy (with the exception of the few more intensive initial ones), and they're a great way to get more comfortable with doing all the things you need to be doing in order to maximize your online visibility.
The key here is to make time to do something, even if it's just 15 minutes here and there.
You know how writers tell you that if you want to write, you should just set aside a few minutes a day and write something, just to get into the habit? Do the same with link building.

If You Have a Nice Chunk of Time

Analyze your backlink profile.
Analyze your competitor's backlink profile.
Make a list of what you have to offer a potential linking partner. If you don't have much, figure out what you can add.
Check your Site Speed Suggestions in Google Analytics. It's under Behavior > Site Speed. I've found this to be incredibly useful in identifying issues that are causing sites to lag.

If You Have an Hour

Find a top referring URL in your analytics that has a very low time on site/visit duration listed. Figure out why they're bouncing so fast. Does your site content that they're landing on seem misleading based on the anchor or the topic of the page that led them there? If they're landing on your contact form page and not spending much time, that might be fine, but if they're landing on a page where you'd expect them to stick around for more than 15 seconds, you might need to update your content, find a better landing page for that link and try to get it changed, or even change the anchor so that it better reflects its target.

Write a blog post about something relevant to your industry, something big happening, etc.
Rework an outdated blog post or page on your site. See what you wrote about a year ago and update it in a new post. Socialize that you've updated it.
Write a response to another blog post on someone else's site and email or tweet to them to let them know about it.
Set up Google Authorship.
Check your site on a mobile device and move around. Do the links work properly? Is everything rendered correctly? With more and more people using a mobile device to surf the web, you really need to make sure that your site works well there.

If You Have 30 Minutes

Set up Google Analytics if you haven't done it already.
Set up Google and Bing Webmaster Tools if you haven't done it already.
Make sure you're listed in Google and Bing Places.
Set your business up on Foursquare.
Read Google's Webmaster Guidelines on link schemes.
Set up a social profile somewhere where you don't have one already, but only if you're prepared to use it. If you're a Twitter maniac but don't have a Facebook profile and can handle both, set up a Facebook page for your business. Set up a LinkedIn page. Set up a Quora account and go answer some questions.
Do a search to find any unlinked brand mentions. "Brand Online Niche" -site:site.com -press -release.
Do some manual rankings checking to see how your results look from a potential user's perspective, and not just to check the spot where they appear. For example, I recently found a result for one of my clients that was ranking at position 3 consistently but the CTR was terribly low. Once I saw the result and how it appeared, it became obvious that people were clicking on the other results (even further down the page) because their results looked much more enticing and mentioned a lower price, free software, etc.
Create a list of Potential Partner sites that you want to reach out to when you have more time. Go ahead and note the contact info, your idea for the site (guest post, potential linking partner, getting added to their resource page, etc.) and any other info that will help you.
Check to see if you are throwing any 404 errors and if you are and there are good links coming to these pages, either 301 redirect them somewhere else on your site (to the most relevant page, or the homepage if you have to although that isn't great for usability) or rebuild the page.

If You Have 5-10 Minutes

Set up Google Alerts (and/or Talkwalker Alerts) for your main keywords and your competitors' brand names, adding to it whenever you have a few extra minutes.
Reach out to a site that's authoritative in your niche and ask if there's a chance you could do a guest post there. To avoid irritating them, first check to see if they have a policy about this. Some have specific rules to follow for submissions, but some state that they don't accept guest posts so check to see if they list their policy before contacting them.

Ask someone authoritative in your industry if you could interview him or her for your site. That builds links and visibility as the people interviewed tend to promote these pieces.
Email or call one of the sites on your Potential Partners list that you created for this exact purpose.
Find more relevant people to follow on Twitter. Followerwonk is good for searching Twitter bios by keyword.

Interact with people on Twitter. This almost sounds silly but honestly, you'd be amazed at how many people do nothing other than occasionally tweet out links to their own content with nothing else ever being socialized. Most people who use social for the interaction aren't going to bother with you if that's how you work social.
Socialize an older blog post that's still relevant. (On that note, when you do write, work in some evergreen topics to increase the chances that you'll always have relevant content on the site.)
Thank someone who's just given you an unsolicited new link. Thank them on Twitter, thank them via email, etc. Just say thanks.
Send an email to your employees asking for content ideas and volunteers to write content.
Ask your employees or customers to ask you questions or identify areas where they're having difficulty. Sometimes when I'm stuck trying to decide what to write about, I'll ask a couple of my link builders to let me know where they're having trouble, for example. It's great fodder for content as the chances are they aren't the only ones having this issue. They can also point out issues that you've overlooked, so it's a great chance to fix something.

Summary

Just remember that building links involves more than doing something that immediately generates a link. Sometimes the process takes a very long time.
You might write a blog post that doesn't do well for months then suddenly someone uncovers it and links to it. You might send an email asking a webmaster to update his or her link to your site because you have a much better target that fits the anchor and it takes 6 months to get a reply saying it's been changed.
This post certainly isn't even close to being an exhaustive list of ideas of what you could do in small amounts of time, but hopefully it can help you realize that little changes can have big results.