At first I earned chump change, but here are some things I've learned that now help me almost make a hearty $5-$10 a week.
1) Keep your "About You" updated, ALWAYS! (100% Completion)
2) Only take high-paying surveys, and mark "not interested" to low-paying ones. This way it recommends ones you'll like – kind of like social media.
3) Always cash out as close as possible to payment days (Thursday and Friday). You can only have one "withdrawal pending" at once. Once you've "cashed out" ~4 times, it's instant cashout – with no wait.
4) Get the Prolific Extension and Mobile App. This way, you'll be sure to be getting the good ones before they get snatched up.
By doing these things, you'll be sure to maximize your earnings from Prolific ^dot co.
My earnings: https://i.imgur.com/1lzTCMU.png