When the androids flick their earrings during a fight, does it do anything in particular, or do they just do it for fun?

i think just for fun

When they flick their earrings, it gives them power to do a special technique (or it just gives them power overall).

it makes the androids more powerful. if you watch the history of trunks, 18 does it right before she attacks and pretty much gets healed. So the earrings are sort of like senzu beans.

yeah i think it gives them power.