Tips I found useful over the years as a GM:
-> say "yes, and ..." or "no, but ..."
-> describe 3 out of 5 senses
-> add sth cool
-> repeat one detail 3 times
-> don't say the monster's name
-> 5 room dungeon
-> d4 1) sunny, 2) overcast, 3) rainy, 4) windy
-> ask the players what they'd like to achive
-> ask yourself is a skill check necessary?
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