In my time of using maps I have on occasion been without something that fits the mood of the game I run. With a bit of stock to work with I bashed out a few maps and thought I'd share some of them. All are as generic as can be in terms of features to make them flexible. With stuff like Roll20 you can layer more details on top of a bare map which is nice.

This one just fell together with a little soft colouring to bring out the vegetation and a darkening of the main trail. perfect for an ambush!
mountain pass.png

I used this as the entrance to a relatively abandoned mine in the side of a mountain. It's a long fall off the edge to the right.
Folgar mine entrance.png

This one I made more recently. Technique was much the same as the first one and to be honest I enjoy doing outdoor maps this way due to the natural shadows on the source material.
Just a hill climb trail.
winding trail.jpg

If your interested, my method here is to find some high quality pictures of rock dirt and vegitation then use masks in photoshop to arrange them as I wish for the map. Add some rudimentary shading to bring depth to the image, perhaps a little colour tweaking and your done! I've got this kind of map making down to about 10 - 15 mins which is handy for those clutch prep moments before a session.

Enjoy!