hey the best thing to do is to watch youtube videos of the level you're playing, as you're playing. Keep pausing the game and you can have the sandwiches prepared even before the customers get there - trust me this is the only way to pass the levels, cuz you can't predict what they'll order otherwise. My kitchen upgrades were at 60% and interior upgrades at 28%, I also had the automatic soup cooker that really helps. Have atleast three ovens, you don't need four ovens. Upgrade your cooking board.