Methods/techniques for learning faster?

This subject kind of made me interested. Is there any proven and working way of learning faster? Not only for memorizing texts, something which many people look for when wanting to study for tests and stuff like that. But learning many other things, for instance, playing an instrument, which requires good motor skills, that take very much time to improve.

When I search about this stuff on the internet, the majority of things I find are about hypnosis, brainwave entertainment, and slow music. But these things just don't seem to be reliable, like inducing myself in a deep trance just doesn't seem to work and listening to binaural/monaural/isochronic beats don't do anything. I didn't test the slow music thing, about 60 bpm music for increasing concentration, but judging by how it is presented, everything looks like pseudoscience.

Do you guys know if there is any reliable ways of retaining information better? Nothing seems to work with me.

There are a lot of memory techniques, I'd reccomend the Memory Palace Tehcnique.

changing topics every 45 minutes Maths, then Biology, or if it was geometry then algebra. Use conectors or strange ideas and link them to math or chemestry, more conectors you have the easier it will be to remember.

Another thing is, practice what you've learnt each week, if you don't practice it enough it will go to a dump xP