The single best thing is to group algorithms by what they actually do - like all the ones that fix your top layer together, all the corner rotations in another group - rather than trying to memorize them as random sequences. Once you see the pattern in what each algorithm accomplishes, you'll naturally remember which one to pull out when you need it. Writing them down helps, but physically practicing each one in isolation until your fingers remember the moves is what really sticks; muscle memory beats reading notes every time. Some people find it useful to give algorithms silly names or associate them with songs, which sounds gimmicky but honestly works for a lot of solvers.