proper weight selection?

[gsrcivic]

just have a question i see alot of differnt things at the gym not sure whats the best rout

i see people doing 5 sets with 5-10 lbs increments each set, i see people doing same work out but with as much weight as they can lift for 5 sets of 5-6 reps and then i see others lift till exaustion

im just wondering what the proper way to go about this

im on a tren and test cycle 320-400 grams of protein a day and im going for mass gain just dont know what would be the best

i know its alot of trial but shits not cheap and im sure some of you have had success with one of these or another?

any input would help alot and sorry if its a supid question

thanks

p-did