I've been gym'ing as directed by Mike Mentzer (an old trainer for former Mr Olympiads of decades ago - died in 2001) and I honestly can't believe how good the results are.
Essentially I've always gone to the gym too hard and never allowed enough time for muscle recovery/repair.
Now I go once a week, do some warm up reps and ONE set of the heaviest I can manage. Then I stay the hell home for about almost a week before going again.
Every single time I return I can lift 10lb heavier than last time.
It's so satisfying breaking a new PR every single week and this is also far less time consuming than every other regimen I've tried in the past.