Do you find yourself worrying about your money not being enough to last you until the end of the month? Are you seriously thinking of subsisting on instant ramen again until your next paycheck? Fear not, as there are lots of easy ways that you can make an extra buck or $100 before the month is over.

Many young people opt to do some one-time gigs, also called as side hustles, in order to earn some money without committing to a particular company or business. The beauty of these side hustles is that you don’t need to have any special skills, nor do you need to make an investment in any of them.

Here are the best side hustles that can help you earn some extra money this month.

Write e-books

This is the golden age of the self-published writer, and there is a large demand for romance and erotica stories online. Reddit user Romanticon makes an average of $1,000 to $2,000 a month writing romance novels.

Be a model for art classes

If being nude doesn’t bother you, then this is the perfect side hustle for you. Art teachers are often looking for people willing to work as models, and all you have to do is hold a pose for 20 to 30 minutes. Art schools and community colleges are the best places to look for an art modeling gig. Models usually get anywhere from $40 to $100 per session.

Deliver food

Earn up to $25 or more per hour when you sign up with Postmates, a food delivery service. It’s simple—a customer orders at a restaurant, you get the food, deliver it, and you get paid.

Take part in a university research or clinical research trials

If you’re living close to a university or college, see if their academic departments are offering people money in exchange for participating in different studies. You can make money testing medications, have your eating patterns analyzed, and the like.

Rent your spare room out

If you have a spare room, you can sign up with Airbnb and have it rented out to visitors. Reddit commenter stella0 was able to make $2,000 to $2,500 a month with this side hustle.

For more, check out Jobs & Hire’s report on the professional mermaid who charges $6,000 per appearance.