I disagree with these suggestions; Uber driving is not always safe, and it’s not very profitable either. Day trading is almost like gambling, and I’ve read stories of people getting addicted.
I’d suggest driving for a Jewish car service; they give generous portions of the fares, largely because there’s so little overhead cost.
Buying and selling things on eBay, Amazon, etc… Can be doable on a small scale.
You could also spend a few hours selling things like business mortgages or other high-yield sales, where one sale pays off significantly; companies like Eastern Union, based in Lakewood, hires people to do this for a few hours a day, not even everyday necessarily.