We always recommend getting a few extra booster packs or trading at local weekly events to upgrade the decks
Depending on your budget, size of your collection, and value of your cards, you can start with a convenient option like a D-Ring binder, and work your way up from there
Skaff has joked that its his most important contribution to Magic
If you dont cast it, put it into your hand. Basically, as long as you use instant speed spells, you can constantly generate value by drawing cards or casting stuff for free, and thats really very hard to beat when youre also messing up everyone elses fun at the same time
Ill be using my own decks as examples, as well as decks from my regular playgroup Now, this isnt to say that everyone should have seven decks I know thats not financially possible for everyone