The most common and most likely answer to this crossword clue is the 6 letter word NICELY
I've seen this crossword clue in The Guardian
N
I
C
E
L
Y
Buddy explains!

The straight part
We know that "in a good way" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case in a good way = nicely.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 NICELY mean?
NICELY adverb- Fastidiously; carefully.
- Precisely; with fine discernment or judgement.
- Pleasantly; satisfactorily.