With anything, consistency provides the best results. I’ve met a lot of people that want to be pentesters but don’t really have any type of schedule or plan to improve. This is one of those fields that require an insane amount of time to master. One of the main reasons I did the videos was to pressure myself into sticking with HackTheBox, as I’m sure many people would be disappointed if I stopped.
My suggestion would be to spend 3 days a week trying to learn. To start out, watch a video of a machine and read some walk-throughs on Monday. Wednesday, try the machine you studied on your own. Friday, attempt a different machine or do the machine along with the video.
Once you’re going, try changing it up. Monday attempt to do the machine on your own, Wednesday (even if you completed it monday) study the machine and take notes on what you could have done differently. Use the third day to read up on something, or try scripting a piece of the machine out to get familiar with Python. Not challenging enough? Try scripting it out in Go.