Razer would be the expert in this category. =P Here's what I use:
Top: Luxury Hat + Myst Case for B herbs and Gift boxes
Mid: Whatever, slotted mid with another Myst Case if you're that dedicated
Bottom: Whatever, Spare Card
Armor: Sky Deleter for +100 HP per kill or any other good armor if you're not a frail character.
Weapon: Baphomet/Doppelganger are staples for Smiths, though Cart Revolution works fine.
Shield: If you're low level, Tirfing is good. Doesn't really matter too much.
Garment: Deviling, cuz all other garment cards are pretty much shat. Raydric and Harpy are wannabe Deviling cards.
Accessory: Blazer is probably most important card you can get. Since they don't stack anymore, Mimic/Plasma/HellPoodle are a nice second accessory card.