I use paint.net, because it's free, and because it has a few features that are handy in drawing basic dungeon maps. If you don't already have it, get it here.
Step 1: Find your background image, and open it with Paint.net. I'm using a plain graph paper background for this project, but you could just as easily use a parchment or stone background, or whatever else appeals to you. You could even use both a decorative background and a graph paper grid by layering the graph paper over the decorative background, and adjusting the Opacity setting on the graph paper layer so the layer underneath shows through it.
|Pretty exciting so far, huh?|
Now, click on each layer in the small Layers window that will appear somewhere in the lower right of your screen. Go back up to the Layers tab at the top of the screen, and select Layer Properties. Here you can name your layers, which is important for keeping things straight. You can also set the transparency of layers, which can be useful in just a bit...
Step 3 (optional): On a blank layer, use the paintbrush tool (set at a size of about 4 or 5) to sketch out a rough path showing routes through the dungeon. I find this to be a good way of laying things out in a rough sort of way, without being too concerned about perfection yet. Once you do that, go back to the Layer Properties menu and turn the Opacity setting down, around 50 or so. This makes the path grid lighter and less obtrusive when you go to draw your actual dungeon rooms and corridors.
|Not the finest example of Jaquaying the dungeon, but you get the gist.|
Step 4: Draw the rooms and corridors! A line width of about 3 works well for this. Make sure you activate your rooms and corridors layer before you start. You can draw freehand with the paintbrush tool, draw straight lines with the line and curve tool (and drag the points on the line to stretch it into a curve), draw rectangles, ellipses, triangles, trapezoids, and more with the shape tool. Rotate as desired using the arc-with-arrows icon that appears near the object. Make sure you get the sizes right and the lines all lined up the way you want them. After creating each element, you can grasp it by the four-way arrow that appears near the object and drag them around to place them just right. Once you move on to the next thing, though, it's set in stone. If you want to change it after that, you'll have to use Undo in the Edit menu. If you do several things in between, you'll have to go back and Undo them sequentially to get to the one you really wanted to change, so it's worth getting it right the first time if you can. Make sure all your lines meet with no gaps.
Most of the rooms here are drawn with the appropriate shape tool. The rectangular rooms with one rounded side are drawn with the line tool, and the final wall is stretched into a curve by dragging the points on the still-selected line.
|Don't worry that the doorways are blocked. There's an eraser for that.|
Step 5: Use the eraser tool to remove any superfluous lines. Zoom in close to do the job right! Use many clicks rather than holding down the mouse button the whole time. If you mess up, you can Undo each click separately, without losing all your progress.
Step 6: Fill in the empty space. Use the bucket fill tool, and select whatever texture pleases you from the Fill bar at the top of the screen. I like Large Confetti for solid rock. Click every null space between your rooms. If the fill pattern spills into your rooms or corridors, Undo and zoom in to check for gaps in your lines. Turning down the Tolerance slider next to the Fill bar will help to keep the fill from leaking through tiny gaps, too.
Step 7: Activate your path sketch layer (if you have one) and make it invisible by unchecking it. Now activate the details layer, and add doors, statues, fountains, stairs, and whatever else your dungeon needs. You can draw them individually, or open up another paint.net window and create icons - little rectangles for doors, circles with stars in them for statues, etc. Crop as closely as you can around the icons. Save them, then go to the folder where they're saved, find the one you want, right click and select Copy. Go back to the paint.net screen with your map on it, and select Paste from the Edit menu. Your icon should appear on the screen. You'll probably need to resize it. Once that's done, drag it to where you want it using the four-way arrow, and adjust the orientation if necessary by clicking and dragging on the arc with arrows that appears next to it. Now, while it's still selected, go to the Edit menu and click on Copy. Now click Paste, and you've created an exact duplicate of your icon, which you can drag and reorient to use in another location. Keep doing this to make all your doors, statues, and such uniform in size and shape. Make sure you get all the items of one type placed before you move on to the next one.
Use the brush tool with a width of 1 to draw stairs, daises, and similar details. Use single dabs of the brush with a wide setting for pillars.
Use the text tool for secret doors. Click near the place the door belongs and make an S, then drag it into position. For horizontally oriented secret doors, rotate the map clockwise 90 degrees using the Image menu, place your S, then rotate it back 90 degrees counterclockwise.
Step 8: Activate the room numbers layer. Click on each room, type the room number, and drag the number where you want it in the room.
Step 9: On the file menu, select Save As. Name your map, and choose a format other than .pdn, such as jpeg or png. The program will ask you if you want to flatten the layers down into one. Do so. Your map is now ready for printing!
If you want to save before finishing the map, use the program's native .pdn format, which preserves the layers.
|Just add monsters and treasure.|