Here are a few more that I try to live by:
Make your deck go round and round. ~attributed to Stef, actually said to me by Adam
(Way more prevalent in engines than anything else, of course, and with a few limits. This mostly refers to cycling and being able to play your key cards more often.)
Think in shuffles, not in turns. ~Titandrake, possibly learned from someone else
(Relevant when gaining/buying cards - if gained during the same shuffle, they will show up at similar times regardless of which turns you gain them on.)
Speed is key. ~jacksepticeye
(Yeah I know he didn't say this about Dominion but it still applies. Some strategies are faster than others, and you don't want to lose because of slow timing.)
Assume your opponent won't screw up. ~me
(It's one thing to hope that their deck will stall or they'll miss a forced win or something, but if you know what their deck is capable of, you don't want to hand them the win just by making it more likely for no reason.)