1) Make your lessons count. Know what you need to know, know the maneuvers, youtube them before you go. Getting you license in 40 is possible, but not easy.
2) Start when you have enough money to finish. If you string it out over a long time, you will need more hours.
3) Know your knowledge, if you ace the oral the DPE might overlook some flying issues.
4) Look at someplace that charges based on tach time instead of Hobbs. This can save up to 50% in pattern work - which will be a large part of your private ticket. Look for flying clubs that might offer this.
5) Compare apples to apples -- if one place quotes 10k and another 6k, one might just be more realistic than the other. How much does an hour of flight cost? Dual? Ground? When do you start paying for the flight instructor for a flight (ie flight time is when they get paid or when they show is when they get paid)? Tach/Hobbs?
6) Look at getting a glider license first and then adding on aircraft. Depending on your area and how quick you can switch to powered it _may_ be cheaper.