The most common and most likely answer to this crossword clue is the 4 plus 3 plus 6 letter word SPIT AND POLISH
I've seen this crossword clue in Financial Times
S
P
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T
A
N
D
P
O
L
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S
H
More clues leading to the result SPIT AND POLISH
- Spanish pilot worried about daughter’s punctilious neatness
- Swap old Spanish tip for smartening up 1?
- Good to put on oldish pants transformed by thorough cleaning
- Ends up with class displaying excessive neatness
- Endless rancour, with European smartness
- Rod and Grace’s ceremony
- Issue with European ceremony
Buddy explains!

The straight part
We know that "smartening up 1" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case smartening up 1 = spit and polish.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SPIT AND POLISH mean?
SPIT AND POLISH adjective- Paying much attention to outward appearance