If by thread idea you mean RP plot/characters/setting then that is, of course, limited by your imagination.

I would recommend having a vague idea of the thread you want to start before looking for someone. Even if it's just the general genre of the RP. Some times people only like to play Fantasy, while others may play anything that has an intriguing plot. If you at least know vaguely what the RP is about you will be more likely to snatch up a companion.

Another option is to find someone who has general interest (have people apply in one way or another so you can get a feel for their style -- so have them PM you the completion of a sentence or describe a certain event. IE: Finish this paragraph in no less than five sentences; Long silver strands wound....). Once you have picked someone/found someone you can collaborate together to build an RP both of you will enjoy.

Hopefully that helps with your question.

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