Haud the hank in your ain hand.
Do the difficult part of your work yourself, or retain every advantage you can.
Haud your feet, Lucky Dad, auld folk's no fiery.
Literally, look to your feet, as you are not nimble: applied when people stumble.
Haud you hand, your father slew a whaup.
Haud your hands aff ither folk's bairns till ye get some o' your ain.
Hawks winna pike out hawks' een.
"It was an unco thing to see hawks pike out hawks' een, or ae kindly Scot cheat anither."—Rob Roy.
Hearken to the hinder-end, after comes not yet.
Hearts may 'gree though heads may differ.