As all my games (Field of Battle, Field of Battle, various Piquet supplements) have cards in them - I'm undeniably hooked on the randomization and characterization capabilities in a deck of cards. As such, the cards have to go someplace during the game.
I'd previously used a double wide business card holder. The unused portion of the deck was on the left, and the discard pile was on the right. It worked "ok", but players had difficulty in grabbing the cards, and cards ended up on the tabletop playing surface. Egad! That is one way to ugly up a game in a hurry.....there had to be a solution.
The unused card deck is placed on the left. As cards are revealed, they are placed in the center section. This makes it easy to count how many cards have been played, and keeps them off the table. After the side's initiative is complete, the played cards are gathered and placed on the right discard section (face up). Easy as can be!
Of course, this solution may not be for everyone. I have a custom built game table with a tray built into the perimeter to hold stuff during a game. The initiative card holders fit in the tray nice and tight, and keep the game table looking good and mess free.