I've been in the situation where my fighter is supposed to be hostile but ended up neutral/friendly without any effort (corsair/outcast rep is a prime example).
Well for the most honest player the solution is if near an NPC base that's supposed to be hostile, fire a missile and make it so, particularly with players nearby who are alligned to that NPC group. Will most players do this? Likely not <shrugs>
My best encounters...pirates taxing right in front of the local police, and groups attacking a player right in front of their home base without the base firing a shot.