All I can say is that if you can afford to go to Europe given the current weakness of the US dollar, then be prepared to have some difficulties on the way back. Europeans are finding it VERY affordable to come here on vacation, and the flights out of Amsterdam tend to be very heavily booked.
Delta out of Edinburgh to Atlanta is often better than average for availability, and Amsterdam to Edinburgh seats on Easyjet are quite affordable.
Really it depends on your non-rev priority. If you travel on an ID90 basis on a carrier other than your own, then you are at the bottom of the list for "space availability". The only sure way is to non-rev over there, and buy the cheapest positive space seat back. In this case, be prepared to subject yourself to extra security procedures due to the fact that one-way ticketed passengers into the US are considered "suspect"!
In any case, if you do go, good luck, enjoy, and be prepared to spend a bundle!