Favourite way to knot a tie, with little effect (6)
I believe the answer is:
petite
'favourite' is the definition.
Both the answer and definition are adjectives. Perhaps you can see an association between them that I can't see?
'way to knot a tie with little effect' is the wordplay.
'way' becomes 'pt' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'to knot' is an anagram indicator (letters are tangled up).
'with' means one lot of letters goes inside another.
'little' indicates taking the first letters.
The first letter of 'effect' is 'e'.
'tie' with letters rearranged gives 'ite'.
'pt'+'ite'='ptite'
'ptite' going around 'e' is 'PETITE'.
Can you help me to learn more?
(Other definitions for petite that I've seen before include "Small, slim (girl)" , "Short" , "Wee" , "Small and attractive" , "Small and dainty from France" .)