If you want something detailed just search "The ultimate consume guide" on GwentDB or YouTube and that'll help you out big time. If you don't wanna deal with that I can quickly give you some advice that I think is important.
-Use Ge'els over Royal decree it gives you a guaranteed gold or silver draw for the next round and you get another shot at your neckers if you didn't draw them.
-Use Summoning Circle. This is really key in my opinion, it
counters Mandrake, Muzzle and also let's you play another Necker R2 if they dry pass after you play Necker as the first card. Also gives you a chance to get another Necker Warrior. Awesome card for consume.
-Greedy Consume doesn't care (much) about card advantage. In most situations you're fine going 2 cards down R1. Going down 3 cards is tricky but still a winnable match for consume. Don't be afraid to dry pass R2 if they have carryover.
-If they bleed you R2 play for as much tempo as you can, don't be greedy. Usually they pass if you play your Brewess. If they don't they'll have to once you eat the 2 Neckers, no deck can keep up with that.
-Always keep track of how many Neckers you have left in your deck and manage them well. Don't pull out too many Neckers if the opponent is killing your low neckers early on. To stop that you can just mandrake one of your first Neckers to 10. Running out of Neckers can happen very quickly and is not a great position to be in for you.
-Be careful with big units. Don't let your Arachas Queen or yourother consuming units grow too big, try to evenly split their power to avoid giving your opponent good scorches.
-If you don't draw any Neckers R1 dry pass. If you don't get any R2 and they push forfeit, no Neckers no chance. No Vran Warriors or Necker Warriors will make it very tricky but still winnable. Not drawing any Neckers or Necker Warriors is rare but does happen, you'll have to live with that sometimes, no big deal.
Those are just some tips I can give you based off of my personal experience with playing Greedy Consume, I still highly recommend watching or reading The Ultimate Consume guide to see yourself how the deck is played and to get a very detailed guide for Consume, it does help.