Hi there! and welcome to the boards!
I am old so I don't really have any current ideas as I haven't participated in a rush week in ages. When we had rush week we really didn't get anything special and I think the most motivating factor was getting a brand new awesome pledge class-sounds cheezy I know
. Maybe you could have a drawing for some cute greek gifts like letter shirts or cute AXO things? Have a drawing each night at the end of the hectic day. In College Station we had a greek store called the greek boutique and they had so many cute things-do you have any place like this where you can get items from? You could single out people too-like the most enthusiatic rusher for the day goes to ........
or the best smile of the day or the best attitude of the day etc...
Good Luck!!