We came up with 'flop' for the lie down command today. Because she tends to flop down often.
MAC, I let my first dog off leash prematurely and had no idea how to properly teach recall, so it was a bit of a disaster from the start. Her recall improved but I ended up only being able to recall her if I yelled "Luna, COME!" at the top of my voice. Fortunately I haven't made the same mistake with Banjo and she listens to a soft chirpy "Come" as well as an emergency one.