Each starting scene should have a "header". That is, it starts by this (replace the text in italics as required):

Date: Date, possibly time (morning, noon, afternoon, evening, night, etc.)
Status: Public OR Private^{* (#fnend1)} (names of players^{** (#fnend2)} )
Setting: Setting/s of the thread
Summary: A keyword or a sentence to describe what is to happen in this thread

Then place the your starting scene under an LJ-cut.

()^{* Public: Anyone may join in;
   Private: Limited to the players named in brackets;}

()^{** Please add all players that join.} () ()