When it comes to units, conversions and general equations, I prefer to not remember things. I like to work it out logically, which is probably why I love Chemistry so much.
Here's my actual thought process, written out on paper as an example:
It means I'm less likely to need to remember formulae, if I know what I've got, and what I need - I can usually fashion together the formulae using simple algebra.
My top tip to all A Level Science students is MASTER UNITS!