I should add that the platform I use for my guitar practice is a program on my computer known as Guitar Speed Trainer. It is really cool since you simply add the exercises into the program and you start it at a certain tempo(beats per minute) and it automatically increments the tempo once the exercise is done. Therefore, you can play along with an exercise, as the computer plays the exercise as well, and the computer increments the tempo at a rate of about 5 beats per minute. You can play along until you can't play the exercise cleanly and so you establish that point as your failure point. What I do is I set that as a plateau and so the next day I come back and I try to increase where my plateau is located, with respect to beats per minute. Here is an image of the program GUI. I only do about five repetitions though and after that it just looks like a plateau and not like what the image shows.