will this do anything

hey guys i've been training for a while and have technique and things nailed with help from my freind. I have been worling with the 3x8-12 reps which i have been getting good gains in i will also throw in some drop sets and rest pause's but i was thinking of
 
3x8-12s
and then on top for one or two excersizes adding an extra set in but of 4 or 5 reps with an added weight like 10kg or whatever i can handle will this help i'm guessing some strength gains or will it just hinder my workout cheers for looking guys

its good to play around with rep ranges and not to stick with the same all the time. ya could mix it up and do 1 exercise per workout with 4-6 range for 4-5 sets preferably a compund movement.
Or if ya want to add in just 1 set of low reps into a few of the exercises id suggest do 2 sets 8-12 then ya 1 set of 4-6 and finish with the 4th set doin 12 reps. this way ya not too burnt out for the heavy set as ya would be doin 3 sets of 8-12 first.

^ Agreed. It will all help. You could do this for a while and then flip it on it's head and blast some light reps out for a while too.
 
For example, at the moment I've deloaded so I start each session with a heavy compound to failure (so squats on leg day, deadlifts on back day and military press / bench on push day) and then finish off with stacks of  volume on 'smaller compound' and isolations. I'll do this till the end of February (started it after some November - Christmas super heavy work where everything was aiming for PB's). In March I'll be going on stronglifts for a couple of months but hammering the cardio all the way to summer alongside this.