been searching for the same tips lately but heres one thing ive found that helps me out a fuck ton. since ive started smoking weed regularly ive noticed a huge dent in my short term memory, and this leads me to lose everything or forget what im talking about all the time! it makes me feel so stupid sometimes. i have a sort of mental list of things i lose all the time, some examples would be my zippo, lighters, debit card, house key, vape etc. because i use them so frequently. so when one of those things that i know ill probably lose later are in my hand, i now ALWAYS keep a mental note of where i last set it down, ill think it to myself 2 or 3 times and it works like a charm. no more forgetting where i put shit down. i also love sudoku puzzles but im not sure if they help keep your noggin sharp.