One of the annoying things about learning a foreign language is when you know the meaning cannot think of what the English word would be! Occasionally there is no direct translation.
The closest English translation for Astuce seems to be ‘crafty’. I heard it in France when somebody would say that they had managed to solve a problem with an ‘astuce’ i.e. they had found an elegant solution. We do use astute, so let’s steal another French word and start using Astuce!
from wikionary French word Astuce
1. Shrewdness, subtlety, astuteness
2. a trick; especially one which is intended to cause harm
3. a tip or piece of advice