I would suggest enacting a two post rule in which anyone on should try to post if there are at least two posts between their last one. This is a rule i've actually imposed on myself, and it generally keeps things going smoothly so long as I don't directly interact with someone who's going to disappear for a long time with no warning. With all due respect it's a waste of everyone else's time to wait for someone else to post before you decide to make a post yourself. Too many people adopt that mentality in a role play and as a result, absolutely nothing gets done or happens because too many people think "i'll wait for someone else to post before me".