Alright here is the first ever true tutorial here at the Cartographer's Corner. This is method I developed yesterday while procrastinating when I was supposed to be finishing my Caliburn map. It's simple and above all fast. This tutorial assumes you are using Adobe Photoshop CS4. Older versions of Photoshop will work though some of the menus or short cuts may be a little different. So let's get started.
Step 1: Create a new project. I used the following settings: Width 8.5in, Height 11in, Resolution 300px, Color Mode RGB 8-bit, Background transparent.
Step 2: Create Clouds. Filter > Render > Clouds
Everything should now look like this.
Step 3: Use Difference Clouds to Create the Base of your map. Filter > Render > Difference Clouds. You'll need to repeat this roughly 15 times so go ahead and just hold down ctrl and press the F key (that will repeat the last filter you used) repeatidly. The final step for this is to expand the layer five times to get a sort of zoomed in version. Click edit > transform > scale then at the top imput both height and width as 500%.
You should now have something that looks like this.
Step 4: Color in the Ocean. Create a new layer and name it Ocean. Then click Edit > Fill and choose a nice blue color that you would like for your ocean. (The example map has R: 62, G: 87, B 120) Your whole screen will now be blue with nothing showing through. Set the blend mode on the layer menu to 'Color'.
Everything should now looks blue
Step 5: Color the Land. Create a new layer and call it 'Land'. Now you'll need to take the magic selector tool and find select a Gray area (NOT a white area). Then choose select > similar. Now select edit > fill and choose a green color that you would like for your land. (The example uses R: 85, G: 100, B: 73) Again set the blend mode of this layer to Color.
It's really coming together!
Step 6: Higher Elevations. Create a new layer, call it Mountains. Now take your magic selector tool and click on a White area. Now choose Select > Similar and you should have only the lightest areas selected. Next chose Edir > Fill and choose a brownish color (the example uses R: 106, G: 91, B:61). Again set the blend mode 'Color'.
And there you go! The map is pretty much done. Everything else is window dressing. You'll see my finished example below where I did some country outlines and some labeling, and a border, but that's all to taste. You can do it anyway you want, or leave it blank and let your players explore, labeling as they go.
From here you can do whatever you want. Experiment, that's half the fun! Email me if you have any questions, or if I have omitted a step from this tutorial (as is likley!).