look for unknown coins with active devs, a unique usecase or protocoll and a strong community to find your next 20-100x.

For me there coins are $DeVault, $Veil, $Swap, $Semux, $BitCash and $XCash

Beside that, for an easily 3x in Dollars (maybe also in BTC) i prefer:

From the medium ones $TUBE, $HPB, $AERGO, $ANKR, $IOTW, $TOMO and  $COVA

The big ones for me are $NEO, $VET, $ADA and $ARDR