Just out of curiosity, do you tend to use pre-printed maps, tiles or boards, or "clean" dry/wet erase mats that you draw? If the former, are they purchased or DIY? If the latter, do you draw them beforehand or during play? Of course, "none of the above" or "other" work fine as answers, as well.
For my part, even though I went out and specifically bought the Master Tiles from WotC (PF GM, but tiles is tiles) I have never used them. I tend to use a wet erase board and draw as the game goes on. I tried preprinting large scale maps (I work at a place with a large scale printer) but I found I preferred drawing. I can only draw to the extent of vision, for example, rather than either revealing the whole thing or using paper to over unrevealed areas.
For my part, even though I went out and specifically bought the Master Tiles from WotC (PF GM, but tiles is tiles) I have never used them. I tend to use a wet erase board and draw as the game goes on. I tried preprinting large scale maps (I work at a place with a large scale printer) but I found I preferred drawing. I can only draw to the extent of vision, for example, rather than either revealing the whole thing or using paper to over unrevealed areas.