Storywriter's Helper

Just starting a new story game with some friends and I thought about this: what to do when you get writer's block? So! Introducing the Storywriter's Helper! Just get a dice and throw and refer to the table below as a matter of some guidance.

Step 1 - Regarding Main Story
1: Introduce a new character
2: Natural disaster
3: New topic/Plot twist!
4: Anonymous encounter
5: Waste time on nonrelated topic
6: Kill someone

This should be simple enough to get you onwards. But if the block is bad, so bad you might want more from the Helper. So from dice roll number one, refer onwards!

Introduce a New Character
1: Sidekick to main character/party
2: Wiseman/Oracle/Elder etc
3: Intelligent animal
4: New villian
5: Family member/Friend of main character/party
6: Return of supposedly-vanquished villian

Natural Disaster
This one actually depends on your story setting. But you could use this as examples or replace them with relevant disasters e.g. Alien Invasion, Bull Stampede. Heck it doesn't have to be a natural disaster.
1: Earthquake
2: Hailstorm
3: Tornado
4: Volcano eruption
5: Flashflood
6: Flashfire

New topic/Plot twist!
I guess if you could somehow incorporate 'New topic - Alien war' into 'Main story - Stone age' then you shouldn't need the Helper in the first place.
1: "Meanwhile, in another part of [insert variable location here], [character] is [verb]..."
2: Reveal a betrayer!
3: "Meanwhile, a secret weapon is being constructed/made at..."
4: Villian kills some unrelated person
5: Someone in the party/close to main character is kidnapped!
6: Totally new unrelated topic that will weave into main story

Anonymous Encounter
Speaks for itself.
1: Ambushed by [insert creature type/class type here]! A fight ensues!
2: Angel/Spirit/Friendly ghost gives advice
3: Damsel in distress
4: Possession by spirit/demon
5: Old friend/family member/member from same homeland appears
6: Neutral [creature type] bars the way

Waste Time on Nonrelated Topic
If you read Douglas Adams or watched Monty Phyton then you probably have some idea of how they can waste time on totally nonrelated topics. For this, look outside your window, or watch some telly, or play some games, and use some of that to help you. Think of it like some sudden cut-scene talking about some other part of the story but has no direct relevance to it.

Kill Someone
Take your pick.