I see what you are saying. When I said that, I really meant: "I don't want it to be my main thing" the stuff i'd do wouldn't be mediocre. But, I guess I'll keep clear for awhile.
Well, at least you are thinking things through. With some deeper thought, you could try to learn routines involving both Cards & Coins...like Matrix.
Or, Earl Nelson has a clever effect using one card and three coins which he calls the $1.50 Vanish. Then there is one I use quite often, where a Coin penetrates right through a Playing Card.
All of these can be learned through proper research. There are many different things that you could perform. Once you learn them, practice them until you are proficient with them. Incorporate all different manners of magic into your routine. You don't have to settle on just Cards.
But, as I mentioned before...if cards are your strength, then learn and grow your act with your deck of cards.