How feasible is it to freelance in Singapore? What are the pros and cons to freelancing?

Freelance depends on the skill that you have. There are some freelance that do not required specific skill like grab driver or grab delivery but these are low return job. Some freelance (self employed) like property agents and insurance agents will require examination and certification before you can start work. If you have some niche skill, that will probably very useful for freelancing.

You can consider doing freelance writing. You can do it anytime, anywhere, and if you can write well the rates you can charge are not bad ($100-400 for a 2,000 word article; content marketing agencies often charge $500-600 for such articles).

Read this guide on how to be a freelance writer.​​​