At the end of the day, it all comes down to the fact that you are just trying to make a living by doing web design or development. Sometimes, if your skills are too specific or you are getting frustrated by a lack of clients, you may want to supplement some of your time with your own project. Your skills are valuable, so put them to use. Whether it is a blog, code snippets, or just tutorials.
While you wait for paying work, consider producing your own themes for CMS or other coding platforms. A content website with tutorials, lists of tools and resources, or news. Either way, if you spend half of your day chasing down clients, use the other half constructively. Even a mediocre site can monetize well, especially if you leverage your social media following.
I would only recommend this route if you are looking to supplement your current client project workload. It is a long process to create a website or app from scratch and have it be able to pay your bills. Generally it’s about 18-24 months (though some do much better) before a content website can begin to pay off from ads or other methods. And you will have to produce a lot of smart, targeted content in order to come up organically in Google.
If you have an ecommerce site or are creating themes, expect to wait about 12-18 months before you begin to see any traction. Partnerships and other relationships can help speed up the process.
Ultimately, your own site can be a nice supplement to what you do with clients, but don’t expect too much. You can also build websites and try to flip them on wholesale sites like Flippa.com, but again, most sales are under $1,000.
You’re better off treating your own website as a passion and welcomed distraction from your daily routine. Just be consistent with your updates to the site, and watch it grow.If you're looking for some serious preparation for your interviews, I'd recommend this book written by a lead Google interviewer. It has 189 programming questions and solutions: