Create a writer website or blog. A website not only demonstrates your technical ability, but it also creates an online hub that allows clients to connect to you. Keep the design of your website clean and uncluttered. Include examples of your work that demonstrate the kind of writing you do. Make the samples easy to find and to read, and make it easy for visitors to figure out how to contact you. . A blog highlights your technical ability and showcases your ability to write blog posts. Your blog can be about different topics than those you write about for your clients. In fact, it should be on a topic that interests you. Visitors will see that you can not only write, but you can also build an online community. A good blog has the potential to earn you many referrals for more clients.
Long-tail keywords are search phrases, rather than one or two words. If you are planning to promote an online poker course for example, you might do some keyword research and decide that the term "online poker course" has too much competition from existing websites, but articles based on things like "When to push during a sit-n-go" don't have as much competition and may yield more traffic.
Know when to wait. Some affiliate programs require a certain level of traffic, subscribers, etc. If that’s the case, I say it’s better to wait to apply for that program instead of applying and hoping for the best. You risk being labelled the person who can’t follow guidelines and you might also risk not be allowed into the program when you do meet the qualifications.
If you have pop-ups and optins on every page, I would have to think that it would be a lot harder to convince someone to link to it. Especially since the pages where you have your optins (and probably receive the most traffic) are probably the same pages that you have your best content on as well that you'd be hoping to pitch in your outreach campaign.