41 Always have a Summary of the episode your working on, and as well as the overall story of the comic. Remember firstly that along the way your summaries shouldn't be set in stone on minor details but should tell you what is basically going to happen, because how you get from point A to B is not always going to be how you plan it the first time.
In my comic Freak of Nature, I was planning on my characters having a much longer means of escaping the facility they were in, instead of reuniting immediately. But the basic summary of how they escaped was still the same, have them reunite, fight a monster, escape.
So long as you have an idea of how the episode or story pans out, you'll be fine, don't worry yourself about minor details so much because they may not always work for a comic.
42 Piggy backing off of what someone said about thumbnailing it's always a good idea to plan out how battled will go down in rough messy sketches of your series is an action based series. I learned the hard way that you really need to plan out different ways for the fight choreography to flow well. Best idea is to watch some of your favorite fight scenes and work on breaking them down somewhat. Depending on your skill you might not be able to get your comic to have amazing combat and fighting, but it's always good to learn how to choreograph fight sequences before hand.