How can my boobs look bigger without a bra?

Answer 1

if you do any sort of working out at a gym, you might also want to consider doing some weight lifting with lighter weights 3 sets of 15 reps, whatever makes you tired 1 - 2 times per week. If you work out your chest/pectoral muscles, you give the appearance of having more lift behind your breast.

Answer 2

try stuffing or wearing tight shirts and pushing them upward i guess?