About the leg extensions and lying leg curls, I do only one set of each just because it feels good.
I often use the leg press to go to failure because I do not want to (dare to) go to the absolute failure doing squats.
About failure and volume: as I have understood, this may cause overtraining for me if I go to failure on most of the working sets. But I am unsure as of how close I should go. So that I can do one more rep? Two more? Or something else? And on how many sets to failure and how many not to failure?
I'm really confused here ppl so help is appreciated a lot.