One thing I'm getting annoyed with at the moment are battle maps. You have an encounter with a group of foes and then, solely to keep track of where everyone is standing, who is flanking who, who has line of sight to where, etc. you, as DM have to build a map - out of Dungeon Tiles if you have them or with paper if you don't.
I mentioned a couple of posts ago that I was running the 'Weave Campaign' and in the second chaper of the first module of this campaign there are a couple of quite large scale encounters. For groups that are used to mostly dungeon delving and city-based games where the biggest rooms are mansion foyers, playing on a 27x39 grid map can feel more like a tabletop wargame than a skirmish. Now consider that a single Dungeon Tile is something like 2cm or an inch square. Even with a conservative estimate that equates to a battle map of 54x78cm (1.77x2.56 feet).
We've only got the one box of dungeon tiles in our group and I don't have enough paper, patience (or space on our gaming table for that matter) to draw two maps which are that big. I'm going to see if I can wing it with some graph paper on a much smaller scale - perhaps 5mm = 5 feet and everyone can just mark their positions with pencil on it.
Also, my girlfriend has almost completed writing her first dungeon crawl. I'm looking forward to seeing what she can do, especially since it's designed for solo play. I've got a lot of experience with solo play and it always manages to throw up problems nomatter what you try and plan for.