Lacking enthusiasm? Not the best way to go shopping (8)
I believe the answer is:
listless
'best way to go shopping' is the definition.
I can't judge whether this definition defines the answer.
'lacking enthusiasm? not' is the wordplay.
'lacking enthusiasm?' becomes 'list' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'not' becomes 'less' (I've seen this in other clues).
'list'+'less'='LISTLESS'
'the' acts as a link.
Can you help me to learn more?
(Other definitions for listless that I've seen before include "Devoid of energy or interest" , "Lacking energy or interest" , "Low-spirited" , "'Lethargic, spiritless (8)'" , "Tells sis to be lacking in energy" .)