After foolhardily promising to provide a tutorial for the style of my pirate cove map, and equally foolhardily implying I would pitch in for this month's contest, I have decided to kill two birds with one stone and do my May entry as a tutorial.
I have decided to draw a ship-wreck as my tactical encounter map. There seems to be a sea theme to the current challenges so I thought I'd shamelessly pander the the audience and continue the pirate theme. I also need a ship-wreck for my current game so it seems to work.
The first step in these maps is to get hold of a decent parchment background. There are many excellent tutorials on how to create such a thing from scratch and I will not go into this here. However, note that a lot of the colour of your map will come from this parchment colour, so make sure it has the tone you are looking for. If you are mapping for a dark game - Cthulhu being the obvious culprit - then dark tones, low saturation and the odd blood-stain are the order of the day. If you are mapping for a standard high-fantasy map then ramp up the saturation a bit, and lighten the parchment colours. The lighter the map, the more colourful it will be later on. If you find the colours are off later in the process, don't worry. We'll be keeping the parchment layer as the background so it can always be swapped out later to test different effects.
Make sure you have a parchment background of the correct size for your final map. Set this to be your background and create a new transparent layer. Name it sketch.
Now, I will be assuming the use of a tablet for this I am afraid. A mouse will also work, as will a scanned pen drawing - I'll add an aside on the pen drawing question a little later.
The first order of the day is to sketch a rough layout of the drawing. This will be the base for the careful pen drawing that will come next. At this point it is all about getting the composition right. I now (after RobA's excellent tip) use the ink tool. This is highlighted in the following image. I set the size to 2.5 (or thereabouts) and have the size sensitivity ramped all the way up. Now sketch (on the sketch layer) a rough design for the map. Don't worry about mistakes, this will never see the light of day. You'll use it as a base for later on. You should now have something that looks like this:
start.jpg
Note that this is not neat. It should be quick to draw and quick to correct. It should show all the major areas clearly and every main feature should be in roughly the correct position.