A good tip, if you get a plug which is a loose fit and spins when you try to screw in, take it out on the end of a screw, remove any dust, inject a bit of adhesive such as own-brand NoMoreNails into the deep end of the hole, press the plug back in, wipe away what bulges out, leave it to set. The next day it will be firmly held, will not spin, and will grip tightly in the hole.