I must learn to gamemaster short sessions!

There are several games in my shelf I want to play. But I don't want to play full campaign, but one to five sessions adventures. Problem is, that my gamemastering style is slow. By slow I mean, that my games always are long.

I tried to run Call of Cthulhu campaign set in modern world in one, maximum two sessions, but last weekend I ran eleventh session. Why? Well, even though I wanted to make one-shot I got carried away with mood and character relations building.

Mood takes lots of time. If I'd run one-shot, I feel that I had to rip so much off from the role part from roleplaying. It would be like fastforward to only those key scenes relevant to the adventure and leaving everything else out. That is hard for me.

I have another CoC adventure planned, and I must try to make it real one-shot, or two to three sessions total. How would I manage to do that?

I don't plan games. Well, I have idea what I want to happen and how I would like to end it and plan for main plot. I should write it down in a timeline to carry out. That would help alot in time managing when I know what happens and when and propably why.

I have enjoyed this Cthulhu adventure, even though it has been fail as it did not last only few sessions what was my original plan. If I want to play all the games in my collection, I must manage the stories and adventures so, that they don't take weeks or months to play through.

After I have gamemastered this one over, I will make real adventure plan for next CoC adventure. It will be kind of a test for me to make short adventure I can gamemaster in one, two or three sessions.

After this one, I will see how I work it out. I am a storyteller, so restricted and focused adventures are hard to manage. Don't know when my gamemastering took this path, but I'll try to fix it as soon as possible. It doesn't mean I won't gamemaster campaigns anymore, but I want to be able to grab a game, throw an adventure and finish it in few sessions.