Teach English Over Seas: You can teach English overseas in many different locations. Ideally you should have a bachelors degree but it isn’t always necessary. Most places will give you an apartment in your contract. http://www.daveseslcafe.com has job boards to search for jobs, ask questions from others, lesson ideas and more.
Teach English Online: You can sign up as a tutor and teach English online. http://www.buddyschool.com is one option for this. When you make your profile, be sure you are professional. If you have not taught before start with a lower pay rate. You can always raise it later.
Sell Your Skills: You can offer your skills on http://www.fiverr.com for various prices and make some cash. Everything from logos, web design and other technical stuff to giving relationship advice!
Utilize Your Skills: Think about what your skills are and use them! If you take good photos and have the equipment, take photos and sell them to tourists. Make jewelry from beach finds and sell them.
Drop Shipping: With sites like http://www.aliexpress.com it is easy to do drop shipping. Find something that you know others will want and take orders, with a mark up of course. I found some great Frozen costumes one year. I placed ads on facebook groups and on my personal page. I kept track of orders. I ordered from the site and entered each persons mailing address. Tada! I made money and everyone got their products!
Write: If you like writing and are passionate about something, consider writing an ebook! http://www.lulu.com allows you to write a book and publish it as an ebook and print book option.
Sell Something: In the past I have ordered phones and tablets online and sold them to locals. We usually frequent developing countries and stay with the locals. The majority of these people don’t have a credit card and can’t order things online. I order one or two tablets and phones and then sell them when they come in. Before long word gets around that I do this and I have no problem selling my wares!
Start an Online Store: You can open an online store fairly easily. Add items that you find along the way.
Rent Out an Extra Room: We rented a large 5 bedroom house in one country. We put 2 extra rooms, both with ensuite bathrooms, on http://www.airbnb.com. This worked well for us. We also put ads for our rooms in facebook groups for the area and other online places.
Tutoring: Offer tutoring in your native tongue. I also offer math tutoring. I’ve also run a preschool in the past that focused on learning English through play.