I use wider orbs than most people, I think.
For the conjunction, opposition and square - up to 6°, sometimes even more
Trine - 5° or so
Sextile 4° or 3°
Minor aspects up to 2°, 3°Usually there'll be another factor pointing to an issue with the planet that's aspected by Chiron, like another hard aspect, or a debilitated position (but not always of course).
I have a wide square from Chiron to Mars (8°) and I can relate to the overall theme of the aspect, although my Mars is afflicted by other planets so that also plays a role.
Same goes for my Moon/Chiron conjunction - it has a 6° orb but it's definitely legit.
In synastry though, it's trickier...