If you have an eye for design and some experience of creating websites, then you could offer your services as a freelance web designer. You will need to create your own stylish website and have a few other projects that you can show potential clients to demonstrate your skills. You will also need to initially spend time emailing businesses to promote your services and find work.
Again, if your blog has a large reader base, then businesses may be interested in paying you to review their services or products. Not only will you get a free trial using whatever these businesses are selling, but you will also get a fee for writing them a review and posting it to your site. Paid reviews (and other paid and sponsored content) can be big money, so advertise this service on your contact page to generate business.
If you have a business, you want to get listed on Yelp! You may not use the software, but some people do, and they use it religiously (and I don’t mean they’ll kill you over it). By listing your business on Yelp!, you’re putting yourself on the map. From here, you also need to start using Yelp! Write reviews of places you go. It’ll be worth it in the long run.
The money is most certainly in the list. If you're at all interested in online marketing, setup email software and create a lead magnet that you can use in your sales funnel. Then, build up that list. It's often said that you can expect to earn about $1 per subscriber per month. If you have a list of 10,000 subscribers, that means you can earn roughly around $10,000 per month. You will need to deliver value and not pitch them on every email, but it is a very achievable goal in a short period.
If you’ve got expertise in a certain area, package up your knowledge into an online course and sell it. This has become a very popular business model for online entrepreneurs over the past several years. The two big websites that are used to sell online courses are Udemy and Teachable. Check out this awesome article by Regina on How to Create an Online Course that Sells.
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.