Like g.r.o.w.t.h. said, rest. It is the first solution that comes to my mind. I always take a week off every two months.
Secondly, use sparingly, seldom . . . forced reps, negatives, drop sets.
All are useful 'tools' but are overused if you read what people are doing.
Straight sets; 1,2, or 3 with the same weight or descending weight each
set to absolute failure. (My version of failure if different than most.)
Full body routines every other day with weekends off or 2 on, 1 off , 2 on
with weekends off is the most I would do, have done. Workouts are brief,
under 1 hour.
I think these things help but ultimately it is rest to prevent and heal CNS
overload and workouts that are brief but brutally hard can't hurt, might help.
Most people work out too much but not hard enough. Working out I think
dominates their lives (especially those that will never step on stage) to the
degree that the stress of all this; steroids, diet, etc., as much as you like
it, can be overwhelming in and of itself.
If you look forward to going to the gym you are not working out hard enough.