Making a map from scratch

[Sharpes]

Okay, so what began as a question about water textures has turned into a bit of a learning exercise about starting a map from scratch. Any help or suggestions (or helpful critiques!) along the way would be most appreciative.

I had all these mapmaking tips from here and elsewhere but can't seem to find them anymore so I'm re-learning a lot of what's involved in making a map from scratch. I'm using Photoshop CS5 though my understanding of it is pretty sketchy to say the least. Perhaps by working on this little map (see below) I might pick up some good tips from others which will give me some confidence in experimenting with more complex processes in other projects.


Original question was:
I want to create a simple map with some basic colours. I see a few maps here have this lovely blue texture for the water. This is probably really simple to do but the steps involved seem to have been lost on me. :S There's probably a tutorial for this somewhere so apologies if I'm asking something that's been covered before.

So, I was wondering...how do I create this effect if I'm making a map from scratch using Photoshop? (I'm using CS5) Is it just a parchment texture with various adjustment layers?

Thanks!


Latest wip:
example 5 with land mass.jpg