There are a few Pathfinder threads along these lines that might help you out with some ideas.
Bestow Curse Ideas
Clever Curses
Here are some ideas of my own:
- Curse an envoy so that he is emotionally destitute and wholly unable to feel anger, happiness, or any other strong emotion. Can only speak in a boring and uninspiring monotone.
- Curse a musician so that he is mute and unable to play an instrument without damaging it beyond use (strings snap, bites down too hard on wind instruments, etc.)
- Curse a mystic so that every time he speaks of his deity/faith and/or prays he speaks blasphemy instead the intended words.
- Curse a xenowarden so that he suffers from severe agoraphobia (fear of open spaces) and becomes a permanent shut-in.
- Curse a soldier to always fumble and drop his weapons whenever he attempts to draw them/pick them up.
- Curse a fast character (operative perhaps) so that they cannot walk at all (0 ft. movement speed), effectively making them a cripple forced to take the crawl action.
- Curse an honorable character so that he is wholly unable to tell the truth ("I am a very bad man who brings innocent people to injustice!").
- Curse a bounty hunter or law enforcement official so that he always sees his quarry as some other type of creature or character.
- Curse a greedy character so that all valuable items look like worthless bobbles and vice versa. Also, make him always tell the truth, or sing loudly when he tries to sneak. Also, make him always miss his mark when making precision attacks (dealing normal damage instead of trick attacks or whatnot).
- Curse a charismatic character so that they suffer from severe self-esteem issues.
- Curse a technomancer with illiteracy.
- Curse a person to be blind, deaf, and mute (with multiple castings)--so that he can't tell anyone he is cursed.
- Curse a person so that they are wholly unable to swallow even remotely solid foods--watch as they suffer and starve to death slowly.
- Curse a person so that they can no longer bend their arms and legs at the elbow/knee joints, causing them to walk around with a strange "tin soldier" like gate.
- Curse a womanizer with Shallow Hal syndrome so that they perceive all physically attractive girls as ugly and vice versa.
- Curse a master orator with Tourette Syndrome so that they must blurt out at least one curse with every breath when talking.
- Curse a liar into always telling the truth.
- Curse a thief so that he cannot pick up anything that he attempts to steal (it always slips out of his grasp).
- Curse someone to smell so offensive as to keep people from coming within ten feet of them. Does not work beneficially during combat. Can be contained by an armor's environmental systems, but then it becomes unbearable to the cursed victim.
- Curse a pervert to always mistake somebody's sex until the worst possible/most critical moment.
- Curse a dwarf so that ale and other alcoholic beverages tastes like bland water--or something far nastier.
- Curse an aquatic creature with severe aquaphobia (fear of water).
- Curse an orc or other primitive that takes cultural pride in their battle scars with flawlessly smooth skin.
- Curse a person who took a Vow of Poverty with an uncontrollable greed.
- Curse a strong man so that they are constantly overburdened, as per the item bulk limit rules (reduce each movement speed to 5 feet, reduce maximum Dexterity bonus to AC to +0, and take a –5 penalty to Strength– and Dexterity-based checks).
- Curse someone with unstoppable crying, imposing a penalty on Perception checks and granting all others concealment against him.
- Curse someone so their age increases by one step (young to middle-aged, middle-aged to old, old to venerable).
You could also emulate the sample curses in the Gamemastering chapter under Afflictions:
Type Curse; Save Will DC 20
Effect In combat and other stressful situations, the victim is affected as if by a slow spell and is immune to effects that would increase its speed.
Cure the victim must hustle (see Overland Movement) for 4 consecutive hours each day for 1 week; it must perform this movement to reach a specific destination.
Type Curse; Save Will DC 20
Effect Each week, the victim loses 10% of its net worth through strange mishaps.
Cure the victim must donate 20% or more of its net worth selflessly, not just to remove the curse.
Type Curse; Save Will DC 20
Effect the victim treats each hour as a day for starvation and thirst and is immune to effects that prevent the need for sustenance or that remove starvation or thirst.
Cure the victim must drink only water and eat only flavorless gruel for 1 month.
Type Curse; Save Will DC 20
Effect After failing an ability check, attack roll, saving throw, or skill check, the victim takes a –2 penalty to that rolls of that type for 1 minute (treat each individual skill check, ability check, and saving throw separately) and can’t try again on rolls of that type. This means the victim can’t take 20.
Cure the victim must spend 1 month humbly and obediently apprenticing to a master in one of its fields of expertise.
Type Curse; Save Will DC 20
Effect Each combat, whenever the victim would take its first hostile action, it is instead confused for 1d4 rounds.
Cure the victim must take no hostile actions for 1 month of active adventuring.