That's great, let's keep it at 4 sets for each bicep and Tricep excersie, try to pick 4 bicep and Tricep excersie.
Now you want to tighten your arms so it won't jingle, those 15 reps you was doing was burning fat and some muscle, mostly fat, so now you want to tighten those arms up, and you tighten it up my building lean muscle.
So for each excersie go for 12 reps for those 4 sets, if you can do 12 reps then next week add 5 pounds trying to get those same 12 reps, when you get that twelve add another 5 pounds so on and so on when you can't get 12 stay at that weight until you get 12 every set
By doing this you adding muscle and tighten those arms up.
Good luck