CeeLo -- Body-Painted Girls on Trampoline ... That's How I Throw a Grammy Party

CeeLo knows ... nothing gets a party started like half-naked women jumping up and down -- which is why the guy booked 3 hot chicks to work a trampoline at his Grammy shindig last night.

TMZ has footage from inside CeeLo's bash at Lot 613 in L.A. ... and it looked AWESOME -- with food trucks and a mobile barber shop ... and oh yeah, HOT CHICKS ON TRAMPOLINES!

CeeLo couldn't have been cooler -- and kicked it with our camera guy while he was gettin' shaved up for the party.

Gotta stay fresh.