I realize people may be pretty unclear on how the game works and that's why they can't think up cards.
I think its mostly based off of Magic so if you learn the rules to magic, you can kind of see where I'm coming from. Although, I do think its hard unless you experience some of it yourself... :/ blah, complications.
Regardless, here's a link. If anyone needs a 1 vs 1 explanation, PM me or find me on IM, I'll try and clear things up for you
http://en.wikipedia.org/wiki/Magic:_The_Gathering_rules
Consider Idea cards like lands, creature cards like characters, and event cards like sorceries/instants. Equip cards are little more unique, although Magic does have some equip cards.
ONE MORE THING: THE TCG I'M THINKING UP IS OPEN TO EDITING, according to rules and technicalities!! So if you don't like the Magic system and think another will work better, discuss it and if most people agree, we can probably change it.