I'd say it depends on how much risk you can take. If you want to minimize it as much as possible, then ask for mandatory collateral however collaterals must go to a reputable escrow otherwise, you'll just appear shady af given your rank. Here is a list: https://bitcointalk.org/index.php?topic=276897.0

I suggest to get familiar with the trust system first (ideally, the whole forum) specially if you'll be doing no-collateral loans since you'll be basing that on overall account standing - basically just an assessment on how likely are they to pay you back/not run away.