Someone asked what you do if you suddenly get lost because of bad visibility or (gosh - IMC). The answer is simple in most of the UK - you simply get QDM from a couple of equiped airfields. When done correctly this can take less than one minute! I'm assuming you can mentally calculate approximately where you are in the UK from the time and heading you have been flying. Even if you can only find one station to call, that will get you a line on the map. If that doesn't work, then call D & D on 121.5 and ask for autolocation, or ask for a "training fix" if you are embarassed.
I was expected to be able to demonstrate rapidly fixing my position by getting QDMs during my ppl training. Is this no longer part of the course? I think it is a valuable technique, as it only needs a radio, a pen and a map.
If you get lost and are near any controlled airspace, then the obvious thing to do is to speak to them, sooner rather than later. They can be very helpful and would rather you called them, rather than they call you (by telephone after you've landed).