Despite not knowing, what exercise, I would train less reps in more sets and progress to failure.
Maybe like this:
6-6-6
7-6-5
7-6-6
7-7-5
7-7-6
Rest day
2 sets to failure tryout
Repeat, starting with 7-7-7 or 6-6-6-6 and so on ...
Just an idea from a non-professional with minimal information about you and your goals...