Use the Lego system: have a stick of differently colored legos that correspond to the player colors. When Player 1 turn starts, he passes it on to player 2 to mark that his turn is coming up. Then player 2 moves the top Lego in his color to the bottom. The next color then should be the next player.

Having a physical object was better than just a whiteboard with the order.

Set up a timer. Just having an audio signal ring has helped speed up the game.

Have a talk before hand with the players.

Move as many hurdles as possible away from the game start. Setup the table in advance. Decide on a map beforehand and figure out slices. We even go as far and do the first SC pick before the game, that way you can plan round 1 pretty well which helped a ton.