Instead of using the black lines to show what the ridge lines are, I'd suggest a shaded relief method...a layer of 50% gray on top, set to overlay, then use the dodge tool to lighten things up (make them higher) and the burn tool to darken things up (make them lower). It's more time consuming as it has to be done by hand but it produces a nicer result. Otherwise, I'd just dump the ridge lines. Nice job other than that and a very good start so congrats.