Obviously you have some familiarity with Photoshop as you nailed the tutorial quickly. I screwed it up bunches of times before I finally got one to match what it was supposed to looklike.
Ascension also has some good tips on doing political borders (i beleive it was in his antique map tutorial).
You could probably still do a bit of a blur on the circular desert then add an outline/stroke around it to maintain the "magical border".
Great start though, looking forward to seeing where you go with this.