Control > Milling, so market away the relic if you need to since you can always get it back.
An early Citywide Ban can be huge vs Palace or Reanimator.
Save your Avigrafts for really impactful units like Merchants, or Wurms from Pit.
If you Desecrate in the same turn after playing Runehammer you save 3 damage.
Sometimes Vara beats can win the game uncontested, but she is also here to break aegis so that you can stick a curse, so you may not want to slam her immediately.
Still very much a work in progress so please leave suggestions in the comments!