Honestly, the best way is both. If a player cannot think of anything meaningful to add to the rp within the IC, then they should ask for [i]help[/i] within the ooc, communicate with their other players, and then come up with something that'll enable them to write a meaningful post instead of skipping. Because if one or more players choose to skip writing a post because they can't come up with something then it'll ground to a halt, and even then for pacing reasons a post, big or small, might be handy for progressing things along.