How to bargain in BALI? Neva did it before but wanna do it perfectly first time!!!?

ok well on the 3 or 4 of January im going to bali for the first time woo hoo!!! but i don't know how TO BARGAIN!!!!! please give me some tips or instruction on how to bargain in bali because i don't wanna pay full price! who ever has the best answer gets 10 points but just plz HELP!