Dominion
In what order do I put cards on my discard pile in Clean-up, and must I show my hand?
Any order you like. Gained cards are already in the discard pile, so Clean-up cards go on top. You need not reveal unplayed hand cards, but the top card of your discard pile is always visible, so avoid putting a card on top you would rather hide. Scooping hand and play area together is fine.