I'm just wrapping up a hunt in Austria and was hoping to get some advice regarding what is considered an appropriate tip for my guide?

Depends, what was the trophy fee? Europeans are appreciative, but from my exp not expecting some outrageous amount of money as a tip. 5-10% of trophy fee will most likely suffice, depending on how the hunt went. I think a lot of what I read on the net is really out of my league, I mean holy mackeril, I'm just a working man. For a 2000 Euro Trophy Fee a hundred or two should be well appreciated, maybe a bit more if you can afford it and the hunt went superb, Waidmannsheil, Dom.