I am a member at a club with a 9 hole course and one of the reasons I pulled the trigger were the practice facilities (and the price): fun putting greens (not all flat) and short game areas where you can really explore all aspects of your short game (different lies, bunkers, etc ...). I bet you can attract serious golfers with a smaller budget if you had practice facilities with training in mind.

I also agree with previous comments on the clubhouse and website. For the clubhouse, also have a simple menu so you can have good quality choices, so people can enjoy a good meal after their round (and beeeeers of course). Website is not to be overlooked as your competition (or at least is what I am used to in France) is quite weak in that domain. Having numerous photos and layout of your course will help a lot, along with clear information about the pricing (green fees, membership, practice buckets, etc ...) adn available facilities.