Find yourself a reliable spotter and test all your maxes. Use full range of motion and don't shortchange yourself. Remember, if you cheat, you cheat yourself. Wraps are fine if you're a raw lifter.. I always use wrist wraps, and use knee wraps only on my top sets (personal preference). Once you establish your true maxes, base all of your percentages off a training max (typically 90% of true max). What this does, is allow you to hit all of your prescribed reps and sets every workout.. regardless of whether or not you've got a spotter, feeling shitty, etc. To compensate for the lower percentage of the training max, I always go for max reps on my top set (technical failure, 1-3 reps in the tank) or work up to heavy singles.