Start your day as a shoeblack? (4,3,5)
I believe the answer is:
rise and shine
'shoeblack?' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'start your day as a' is the wordplay.
I cannot quite see how this works, but
'day' could be 'd' (abbreviation for day) and 'd' is found in the answer.
'as' could be 'in' (I've seen this in other clues) and 'in' is present in the answer.
'a' could be 'an' and 'an' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for rise and shine that I've seen before include "Get up, military style" , "Cheerful (!) invitation to vacate one's bed in the morning" , "Get out of bed smartly!" , "Look lively" , "as will the sun bright and early?" .)