How to memorize 4x4 parity!
OLL: (Rw U2, X, Rw U2, Rw U2 , Rw' U2, Lw U2, Rw' U2, Rw U2, Rw' U2, Rw'). You can forget about the u moves if you just remember that there's a U2 after every wide move. Now you just have to memorize Rw, X, Rw, Rw, Rw', Lw, Rw', Rw, Rw', Rw'. We can remove the rotation from the equation cause you can just remember it's in the beginning. Then we can use a technique that I know from card tricks, cutting it up in pieces of 3. So we have 3 Rw, then we go down 3 times with Rw', Lw, Rw', then we have a normal Rw, and then we just do Rw' until the parity is solved.
PLL: (r2 U2 r2 Uw2 r2 u2) This is very easy. You just keep doing r2s and then variations of U2 in descending order. r2, top layer, r2, add the second layer from the top, r2, remove the top layer.
These tricks might not work for everyone but they sure helped me out a ton!