Recently I decided to just make a simple sheet to track them, and it was pretty easy to make it so that you could do pretty much most (if not all) of an adventure's Encounters all on the same page.
Feel free to use it in your games, and hopefully you'll find it as handy as I have (though I've only used it once). It's pretty self-explanatory, but here's an example of the one I used last session (for "A Darkness in the Marshes"), just as an example:
