Training is pretty simple IMO. It's about making sure you are absolutely recovered - and then some.
If something isn't increasing/improving every workout, you are hitting that body part too often and/or subjecting it to too much volume.
You also need to remember training other body parts on separate days has a systemic effect and will impact recovery.
So relatively recently for example:
I was stuck on 190kg on supinated lat pulldowns for 5 reps to failure on my working set for 2 consecutive workouts. (Just positive failure as I train alone)
This is after heavy barbell rows, which incidentally I have had no real sticking points with for a long time.
When I got to the next workout where I would usually perform them again, I simply omitted them and just did the barbell bent over rows and some pullovers, which both improved again.
When I came back to the pulldowns a fortnight later, I could do 8 reps to failure.
This is how I personally make improvements, I omit the relevant exercise to absolutely ensure overcompensation takes place.
As long as you are hitting that body part with some other movement/s, you are not going to lose any size and strength on the movement omitted. On the contrary.
