I haven't seen this mentioned much, partly because it's not guaranteed to come out.
Both of these guys are pains in part because they can potentially have multiple miracle cards in their hands at any time - for Miracle that's the only real threat, and the reason why most god-farming decks have 90% against him. Morte has given me a lot more trouble, in part because I'm often in a race with poison or something else when I get him low. Rainbow also does the miracle trick, but there's nothing you can reasonably do to stop it.
Here's the tip for the other two though: miracle takes 12 white quanta and drains your pool.
A lot of the popular decks have ways of getting creature-based 'destroy' abilities, and a pulverizer isn't a bad bet either if you can get your hands on one. it's entirely possible to burn off all but 2-3 white towers, making a second miracle a 2+ turn cast or more. Once you've got him to that point, your late game win is pretty much assured, as long as you're doing ~67 damage a turn, almost assured by turn 20 or so.
Morte's even easier, and the reason for this tip in the first place. He's only got photons to give him quanta. Deny him the photons early on and you'll never see a lot of nasty white stuff come out, but that miracle will never hit the floor. A lot of people have mentioned Morte being fairly easy and that he didn't pull out miracle that often. I suspect it's more due to quantum denial through photon destruction than him actually not having a ton of copies of that card at hand.
These aren't really game changing tips, but they can help with your focus in the mid-game against both