Players and money. Try and make your rental packages as appealing as possible in terms of bang for your buck. Get the word out around town that it great way to kill a Saturday. Invite a reporter out to play. Offer him a free rental package or something. Maybe develop a like a "B-Day D-Day rental package" and include ten rentals and two cases of paint or something. I don't know what is practical for you and what is not. But some gimmick to spark the interest of potential renters.
Goose River Paintball has become a premier field in the area through the efforts of their volunteers and Rick and Ryan. These are guys who go out and make sure every single renter is always taken care of and customer service comes first. Not many people in the area actually know about the field. For example a lot of outlaw ballers ran out of their usual sporting goods store for air filling and found GRP on facebook came to get air, saw the field and started coming back.
The best I can say is try and get a crew of regulars and make customer service your #1 priority.
Assuming you are talking about By-Pass paintball. Make sure locals know about the field, seriously often a field can be 1/2 mile from someone and they don't know about it (this happened at Goose River Paintball last weekend, the only reason they found out about it was because they saw a car with out of state plates pull into the field).
Make sure your regulars have reasons to invite friends (referral bonus!). Try posting flyers, in local stores. You have the air force base there, give military discounts. You also have access to oil patch workers, they have expendable income.
Seriously, marketing it probably the biggest thing you need to figure out to make it work.
Do exactly what was stated above and develop a local crew of regulars and organize dates to go to the field. Be sure to include everyone and maintain a positive attitude.