Maybe consider some floating plants as well as some dither fish.
I've noticed these guys really like plant coverage and are more active with other fish swimming around. A smaller species of something being active out in the open means there are no predators around; this makes them feel more comfortable.
and don't worry, those guys will soon realize you're the food provider. Mine must feel my foots steps because they're all up at the corner I feed from before I even get to the tank.