Arrive well dressed, look sharp (4,2,6)
I believe the answer is:
make it snappy
'dressed look sharp' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'arrive well' is the wordplay.
'arrive' becomes 'make it' (synonyms).
'well' becomes 'snappy' (I can't justify this - if you can you should believe this answer much more).
'makeit'+'snappy'='MAKE IT SNAPPY'
Can you help me to learn more?
(Other definitions for make it snappy that I've seen before include "do it quickly" , "step on it" , "Get a move on!" , "Come along" , "Be quick about it (colloq.)" .)