Books tend to offer card advantage, so card draw, discard, and hand size will be recurring themes, but we could see lots of others
There's plenty of utility in between those extremes
Then things get complicated, but that's the basis
Protect your collection from the scammers
Forest of Giant Plants The Stadium card that got banned for being too good, Forest of Giant Plants, is a legendary piece of tech in pretty much every meta Grass-type deck during the time, and was a key player in allowing the player who goes first to put their opponent in an item lock before they even get the chance to play
I am a big fan of lifelink in Commander these days, and Metamorphosis Fanatic is my kind of card