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.
Sell stuff online. If you have high-quality items to sell, there are a slew of online marketplaces you can use. Just make sure you understand the fees associated with your sale before you take the plunge. Where neighborhood Facebook pages and Craigslist ads are free, many online marketplaces or consignment shops charge for ads or require you to fork over a percentage when you make a sale.
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.