You can't take a PPL skills test unless you have the minimum of 45 hours flying training so....
Some non-geographical rule of thumb advice might include looking for a flying school that operates diesel PA28's or C172's as they are cheaper to learn in.
An RTF or FTO close to your home base to cut down on fuel bills and increase the chance of basing yourself at the airfield which can be an aid to learning and provide additional flying opportunities.
Be in a position to be able to pay for the whole course (not up front though!) so you can fly as often as the weather allows. Invariably people who learn this way take fewer hours to complete i.e. they do it in 45 hours rather than more and it's usually a lot quicker in terms of time scales.
Buy only the required PPL kit and course books but try to buy from ebay or an ex PPL pilot - look at the noticeboard / ask about at your local airfield(s).
Try and befriend a pilot who is keen to share their knowledge and experience together with a little cost sharing flying. Whilst this is not official training and does cost you a little more, you can learn a great deal which will improve your overall performance and confidence in your actual flying training.
Stop going to the pub
Others may be able to add their own cost saving ideas...