“ If you want to add a 'supernatural' touch to your campaign, define the rules of magic and the universe. Make your players comfortable with those rules. Then your new supernatural creatures must then break those rules.”
“ A place where a fertility spell has gone wrong.Kisses can lead to pregnancy, any fungus infection runs rampant, corn grows as soon as it is planted,ect.”
“ The PCs come across a wild thicket of luscious looking blackberries. They eat the berries and become drunken fools. Later they find out that the berries were part of a fae garden and were intended for fae wine. In payment for stealing the berries, the mischievious fae make life inconvenient for the PCs. Horses are untied, water skins are drained, spare clothing is drug into the water, etc.”