Building a blind box is kind of hard to explain. You really need pics so I attached a couple for ya. Carefully fill the box with green leaf lettuce and parsley. Make sure you wash them and get rid of the bad leafs. (brown spots). You don't want to sink the food into the garnish so make it stand enough on top to pop out at you but don't build it up too much so you can't close the lid.
Making the boxes is probably the dullest and most time consuming job during a contest but the time you spend can pay off in the end.
The ribs placed 2nd and I think the chicken was 5th. These are a few years old, since then I have switched to all parsley in a box. I don't have any of those pics but I'm sure there are some floating around. Good luck to ya.