Another tip that I got from a cooking show, if you are making a cake from a mix, when greasing the pan, instead of sprinkling some flour onto the pan, sprinkle a tiny bit of the powdered cake mix. Then you won't have a flour taste to your cake and, if it is an uniced cake, you won't see a dusting of white on the top.
MeShell, is the cooking spray at Tescos the aerosol kind? The cooking spray that I bought when I first moved here is a pump (like hairspray) and it is really pointless for getting an even layer of oil. Is that what you mean when you say spray vs. squirt?