5X5's can be considered Power BB'ing. In the true sense of this training method, the style is a little looser than normal. But suit yourself in this regard, do the exercises by the book if you wish. It can adapt very well to bicep/tricep, delts or even abs for that matter. Cheat (slightly to get the weight started..every rep of a set is cheat style) curls can add thickness and a more rugged look to the biceps. (looks kind of cool when wearing short sleeve shirts and the lower belly of the biceps bulges out even when relaxed) Lateral raises (for example), also in a slight cheat style, give delt thickness and mass. Start with the DB's in front of the body and swing them up to shoulder height. In any event, 5X5's can produce muscle mass, in a rather short period of time, if approached with serious intent.
The original purpose of 5X5's is to do only one exercise per body part. The main idea being to keep the workout brief and to the point. And also to help with the recovery time between workouts. 5X5's can work well with a full body workouts, using only compound movements. Usually the squat, bench and BB rows making up the program. But adding extensions exercise (5X5's also) after a compound movement can work well also. Something like benches followed by flys, BB rows followed by pullovers, presses followed by lateral raises, etc, etc, etc. Pick your poison, whichever version works best for you.
With any Square Root program (5X5, 8X8, 10X10) you keep the reps to that amount. In doing 5X5's you find the weight too light or too heavy, allowing you to do more or less than the 5 reps, than lower or increase the weight on the bar. Another matter is , you do not want to go to failure on any rep. Even if it's the last rep of the last set.
A main problem is that too many well meaning trainee's try to tweak a BB'ing program to suit their misguided needs. You do not do 4 rep or 6-7 reps on a 5X5 program because than you are not doing a 5X5 program. You are doing something else. And than when not getting the results you think you should have, you will blame that specific 5X5 program as being crap and wasted time invested.
This happens a lot with GVT (10X10) because quite a few people do not understand this simple protocol. Or get mistaken notions from people who know less than nothing or do not have the training experience, let alone give out advice. Sort of like the blind leading the blind. Good Luck.