You could be editing already pre-filmed footage for clients. 

Clients can vary from digital marketing agencies to mom-and-pop shops. 

The only thing you need before you start is a portfolio. 

To gather a portfolio try to create videos for your friends and family. 

Another way is just to create videos in the niche you are interested in to show off your skills.

Video editing skills;
Editing software (Adobe Premiere, Fincal Cut Pro X).

$1000 - 3000 monthly

✅ Flexible hours

✅ Creative work

✅ Easy to get a job

✅ Future-proof

❌ You can encounter a creative block

❌ Easily can get boring

❌ Hard to scale

The best way to get clients for this side hustle is by having social media presence and having testimonials. Another way to get work is through platforms like Upwork and Fiverr.