I want to suggest firstly, a means of implementing in the text box for making a post in missions in also include a forced template where it has text formats showing something like the following (suggested by Akab)
Summary: What we will be doing and why you think it would be a good idea.
Date: Day, year and even time. You can also put how long it is if there is a set time.
Location: Is it set in one location? Global? Online [put the link]?
Requirements: Is there an age requirement? Do we need money or any other materials?
Details: This is where you would put the plan. What exactly is going to happen and how.
Other: If you have anything else you want to include. I think this would be a good place to put any questions you have any.
Contact: How people can contact you if you want to give out this information. If not you can always write how often you will be checking the thread. If you use the chat rooms you can always post information for that so they can ask you questions.
This as they already said, would make Missions a hell a lot more organized, and because it's forced, more will do it. Plus I think making it where if the sections are not filled in, the post will not post, hindering those quick mission makers.
Secondly I want to suggest implementing a poll function in if possible where people can actually vote on whatever the poll is about. Maybe it be used as a temporary like/dislike function, or a poll on such things like actual suggestions on this board. This way we get an actual number of who likes a suggestion and those who don't based on comments and the polls.