Over 65 years of crosswording means that some things just stick in the mind. Also
Bradford's Solver's Dictionary is indispensible for the serious solver -it is used by a lot of the setters.
Today it is set by Paul who is the heir apparent to Araucaria.
It is a cracking puzzle, possibly aimed at the more experienced solver but give it a go. Come back on here for explanations if you are stuck, or work back from the answers in tomorrow's paper.
A couple of clever clues-
5a Flying tooth (7)
18a Site coordinates parental choice? (3,9)