Also I would imagine a nice way to use ink to your advantage is ink pressing. For anyone who doesn't know about it you need a roller, a tray you don't mind getting dirty and ink.

You roll the ink out evenly on the tray, quite thin (so their is nearly no shine in the light, though their should still be some.

If you have applied to much you can place some blank or scrap pieces of paper and press them onto the tray and lift them off having them take off some of the ink. Do this as many
times as you see fit.

The ink should not mark the paper on touch but instead should only mark the paper whenever and wherever you touch the paper.

You should draw the map on a piece of tracing paper and when you want to do the the full version simply lay down a piece of normal, blank paper onto the ink tray, flip the tracing paper over and place it onto the tray, on top of the blank paper so that it appears the the map is all backwards and then draw over it all again.

Wherever you want their to be shading simple smudge your finger onto the tracing paper. This will lightly cover that area of the map in ink. The more you do it the dark it becomes. Lift it off and the map is complete.

Fear not if it has smudged in areas you didn't want it to because you will still have the tracing paper copy to repeat the process. However this accidental smudging can
create quite a nice effect and it can sometimes come out better than you expected. Don't be afraid to mess around with it.

I'm sure there are lots of videos on youtube of this so check them out.