Take it seriously. Yes, you’re applying for an online job. Yes, you can do the work in your underwear, but that doesn’t mean it’s not a “real job”. You must treat it as such or they aren’t going to treat you as a serious candidate. You aren’t the only one who wants to work in their underwear. In fact, the competition online is likely higher than it is in your local area.
If you are a confident web developer then designing your own themes is an obvious path to follow if you are looking to make money online. ThemeForest sells a wide assortment of developers themes, including themes for WordPress, Shopify, Weebly, and Tumblr, to name a few. Once you have created your theme, get it accepted onto the ThemeForest marketplace and make money each time it sells.
Mechanical Turk: Amazon's Mechanical Turk is a resource for doing human-intelligence tasks, or as the site commonly refers to them, HITs. You get paid a very small fee for any given HIT and you'll need a good deal of volume to make a substantial amount of money. But it is a resource you can use in your spare time to generate a small income online.
One of the cool things about Google AdSense is that it's so easy to get set up. If you have a blog or website, you can sign up for a free Google AdSense Account. From there, Google will give you a unique code that you will paste onto your website. Google takes it from there, tracking your page views, traffic, and earnings on your behalf. There is no upkeep or maintenance to get this thing going, which makes it a no-brainer if you have a website already.