A revolt or attack happens against a strong city/kingdom. All the losers of the battle that can be captured are brutally crucified along the roads that enter the kingdom to show their strength and as a demonstration of what happens to their enemies. ... a long road, decorated with hundreds of dying crucified soldiers... You see them bleeding, you hear them screaming and whispering for help. Do you really want to enter this reportedly peaceful kingdom?
Small tavern in an out of the way town. Serve a wonderful delicacy that is simply outstanding. It is a creamy white consistancy, sweet, good to eat alone or a sweetener on any dessert. If the explore or ask they are shown where they get it. They breed a group of large catipillars or some other type of insect that basically spit the product onto a setup that they created for that particular reason. Or maybe the delicacy is the byproduct of feeding them something. Instead of city can be a traveller offering the food.
Mining in a certain area turns all exposed skin (maybe just parts that are actively disturbing the chemicals that cause the reaction) of the those doing the mining to a dark blue color. Will wear off taking as many years/days spent in the mine. ... meeting a party of blue-skinned humans armed with pick-axes etc. Strange disease? Demon offspring? Curse? If they meet only one ex-worker, they will very carefully listen to any stories he says, no matter if drunken or insane, or just makes up to get a beer.
Diseased people, (leprosy or any other such fear inducing disease) when traveling, will often times wear a cloak that entirely covers their body and ring a bell as they travel, used as a warning for any others to stay away. Could be used for a disguise or safe passage. ... you meet strangely cloaked people, sometimes ringing a bell. "Please give us something to eat, mighty heroes!" This is time to show how good they are.
Herbalist in the group mistakes one plant for another and mistakenly poisons the group. Not to death, but pretty darn ill with recurring symptoms until the cause and cure are realized. (Local people may be able to help rather easily. "You ate Dragon's Rot you fool, looks and smells just like mint except it has these small thistles on the root. Only grow in the Hornwood Forest, that must be where ya got them. Eat this and you will feel better in 4 hours."
PCs camp for the night in a dry pine forest. Fire skill of the person that made it is usually pretty good, but during the first watch the unexpected happens: a spark lights the surrounding woods and a brush fire quickly starts. Be quick or it could turn into a disaster that could affect the entire region.
Could come across a band of refugees. Could have been thrown out of their town by a tyrant taking of their land, bought out by somebody unexpectedly, fleeing a battle they know is coming their way. Could be proof of what they are searching for, hints and tips of what is to come, or just to broaden the reality of the world.
Young kid from last town has been following the PCs and doing a rather good job at it. PCs weren't expecting to be followed so weren't worried and the boy/girl was careful. Notice the follower a couple days out of town, kid ran out of food and started getting careless. Followed the 'mighty adventurers' to see if he could join them. Father is a wealthy merchant. Bring him home, bring him with, send him off? What do you do with an unwelcomed guest.
Rain slowly builds, thunder and lightning continue to roll in. Road muddies, horse/wagon getting stuck in the mud. Thunder strikes coinciding with a deep hole a horse just walked in, horse panics, breaks its leg (maybe just sprain?). Horse is decompacitated and the rain just went from pouring to an all out monsoon. Shelter needs to be found, horse needs to be taken care of, covered in mud, add the posibility of items being lost to the confusion with the wind and dealing with spooked animals.
You come upon a ruined building in the back section of a city park (or other out of the way area of the city). The ruins are fairly overgrown. All that is really standing is a doorway and its frame. If you pass through the opened door, you travel to a different world. If the door closes, there may not be a doorway back to get you back.