First, green and green blue isn’t the same.
With green, you’ll want to have taunts and big bodies to trade things like Dune Drake or the 5/4 Demon (or Crusader if need be). You’ll also want smaller bodies that can kill the 1 HP guys, and collect faeria defensively. Healing is absolutely useless, except in end game when you want to ensure you’re not going to get killed by surprise haste. The idea is to develop fast lands to cancel all the spots around your orb (don’t hesistate to builds two Forests/Explore +1 forest straight to meet you opponent and block its advance, if you can drop a creature there. Then, you fill with forests if you can, or double neutrals to stop your opponent from setting a land deep. Use things like Earthcraft or Elemental to speed the process, be careful of a haste then desert. That’s your priority. If you succeed, then you’ll want to set up harvesters on both sides, and you’ll slowly get the advantage back. The rush deck draws more than you, so you may even stay in defense and win by fatigue, or set up a counterattack by building double neutral, then forest and drop something like Verduran Force (3 turn killer, it’s a good counterattack). Your best creature in this matchup is the 5/6 Taunt (cant remember the name) which stops hastes and trades well or Living Willow (Willow’s good against hastes, but bad against big bodies, so try to play it with something else to defend it).
With green blue, it depends on what you play (Apex ? Enchant ? Something else ?). The same strategy might work, or you’ll want to build on the sides to double collect (maybe more if you use Sturdy Shell and manage to set it in the double collect position). The matchup should be harder than mono-green as you have to set up both colour of lands, as well as protect the most important spots, which are 1) the spot next to faeria well 1 tile away from orb, on each side (Siege spot), and the spot 1 tile away from orb, which let the opponent attack from two way, on each side (Assault spot).
In both cases, you want to avoid being hit as much as possible to avoid growing their Crusader : set up Taunts, put minions in the way/on desert tiles. Not an easy task, might work or not depending on both your hands and decks. And what’s important is to counterattack at some point. In a few games you might win by defending, but in most cases, if you only defend, your opponent will store resources and might launch a big attack that you won’t be able to defend. Once you’ve managed to defend correctly, you have to step up and bring him down before he stands up back. Also, blue has an edge over Crusader : Unbound Evolution.
That’s all for me, can’t say much more without knowing what you play, and it all depends on situations, but you have a rough picture of how to fight back. Good luck
Also, if you need, you can ask for live coaching, we’d be glad to help