I don't like using the actual mechanics of a grid for movement and such, but when drawing out maps I often had them drawn out on paper or on a mat sheet like the chessex grid one and I would put those plastic sheets for overhead projectors on it, tack it down, and used those markers your supposed to use to draw things on the sheets when the situation called for it. All characters, NPCs, monsters, and anything else where either a miniature somebody had for themselves or a slip of paper that went over the plastic sheets to represent it. Washing them off was simple. Drying them if you had to quickly reuse them was a pain though. One of the advantages is that I could have different sheets pre-made so I could quickly plop down something the players weren't expecting without having to go to a lot of trouble drawing it out on the spot. Often it was good in extending the life of my grid mats.
I don't think my system was the best though. I've seen some pretty elaborate setups in a variety of ways that put mine to shame. Of course they were a lot more expensive. I just wish I could have convinced my players to use pins and scaled down maps in some situations though because drawing out a very huge dungeon or complex was sometimes a pain in the ass (and I would sometimes run out of physical room), but even a lot more so outdoor areas or areas with huge spaces where line of sight and effect was very far out.
I don't think my system was the best though. I've seen some pretty elaborate setups in a variety of ways that put mine to shame. Of course they were a lot more expensive. I just wish I could have convinced my players to use pins and scaled down maps in some situations though because drawing out a very huge dungeon or complex was sometimes a pain in the ass (and I would sometimes run out of physical room), but even a lot more so outdoor areas or areas with huge spaces where line of sight and effect was very far out.