That's pretty much exactly what I do. Except I keep my "plot document" just at the bottom of every chapter doc (scroll way down to read, scroll back up to write and when you finish a chapter, just save the same doc, renamed for the next chapter and delete the chapter meat, keeping the ever evolving "plot document" at the bottom of the current chapter). Re-reading the scenes just before where you are, and then examining what crucial scenes and bits are coming up is a must for me.

Sometimes when I'm at a sort of filler spot I'll instead work on a rough draft of a future scene that interests me more. Eventually I'll figure out exactly how I want to get there and end up writing that.

If it's been a long while or I'm feeling lost, I also like to write up several paragraphs about everything left to cover and the rough plan to cover it in. Even if you know it, and have an outline, or notes, or a plot document, forcing yourself to write it out again helps to sharpen the plan in your own mind. Having a friend to IM/email or a forum where you can openly discuss crucial future plot details also helps.

The thing is, if your story doesn't have an ending or conclusion you're excited to get to, then you're shit outta luck. That's why you shouldn't start unless you know where you're going to end. Too many great abandoned fics out there because they got started and then got stuck.

 

Oh, I also tend to list all the major plot points of the book/anime/manga (because most of the fics I do are AU from the start) and think of how I could either do it different or if I can think up a completely new path that an bypass a few of them. Of course in the beginning it tends to be the former, branching out into the latter.

Aekiel