Mucks last post had a pretty good thing in it. In most missions I have either planned or been a part of IF there was time for it the planner could and did insert planes that someone asked for while waiting.
This ends up creating more people wanting to get into the mission and then the next mission they put up as well. Because the planner has opened up in a non-verbal way that they listen to imput from the people flying with him.
Also I think it helps when the mission planner/leader rotates his flying through all the aircraft in his setup. When I typically fly a mission I put myself in an attack bird or a bomber. Because I like to be where I can see what is happening and not relying on information second hand. Other than fighter information.