Slowly and deliberately, focusing on the parts that elude me (i.e., I'll skip the intro and other sections that are 100% solid in muscle memory). Paying attention to fingerings. I'll usually focus on 1-2 pieces at any given time.
But I do go through spurts, where I practice every day but then for whatever reason step away from days or 1-2 weeks, which might be killing the neuron connections.
I also round-robin my nighttime between piano, guitar, and composition, which probably ain't helping.
I also play piano, guitar, and compose, and I used to struggle with memorizing, but I've been reading a lot of piano practicing theory and have drastically upgraded my finger memory, mostly by using these resources:
Loosely, stop using sheet music except when you're initially memorizing the piece, learn music in much smaller chunks than initially expected, and play entirely from memory whenever possible, even when you're practicing the repetition of something.
The fact that you can remember music easily in your head means that if you spend 1-3 years really banging out the hand-brain connection, you might be able to rocket your playing forward. Raw improvisation where you think of the melody before you play it will help, too, if you don't already do that.
It'd be amazing if it's not a memory problem (at least, not any more so than for most other people who learn piano) but just have to learn a new way of connecting them neurons.
I wouldn't be surprised if you find yourself with a much greater facility for memorization. The only caveat is that it takes longer to get to the point where you can "play through" a piece, which feels less efficient than learning by sheet music, but I find that my ability to interpret and make phrasing choices with memorized music is much greater than it is with music I'm reading.
I completely agree; Bernhard's posts made me realize that even professionals do not necessarily know the most efficient methods for teaching and learning, and that it may be necessary for students, even as amateurs, to challenge and seek advice beyond what their teachers are capable of, despite the existing gap in skills.
But I do go through spurts, where I practice every day but then for whatever reason step away from days or 1-2 weeks, which might be killing the neuron connections.
I also round-robin my nighttime between piano, guitar, and composition, which probably ain't helping.