Tough business to try and break into but good luck.
My list, in somewhat of a real order:
1. GOOD range balls. Not limited flight. If the range balls suck I won't go.
2. Flat AND slanted hitting areas.
3. Target greens, marked yardages to targets
4. Practice putting area
5. Practice chipping area
6. Practice bunkers
7. Cafe/snack shop
8. PGA Pro

9. Club cleaning station(s)
10. Check out Zone22 here for range ball equipment
http://www.thegolfspace.com/readygolfer
11. Friendly staff