During two visits in August 2016, I checked the spotting locations which were mentioned on several spotting guides on the internet, please find below my updates:
There is one runway (north-south) with the terminal on the south-east side. There is a platform connecting 3 main areas from south to north: visiting (biz)jets, main terminal, local aviation. From the platform there is a taxi way parallel to the runway to the north.
1. There is a small exit from the main road at the end of the runway where you are slightly elevated compared to the runway.
2. There is a small clearing between the trees, this the closest location next to the taxiway and main runway.
3. Slightly further away from the runway and taxiway but with more overview and an overview of the platform.
4. At the main runabout to the right of the terminal there is a small exit which runs parallel to the platform, between the hangars you can oversee the northern part of the platform.
5. On top of the old car park you have the best view on the whole airport, unfortunately it is closed and fenced off.
6. On top of the new car park (most southern part) you can overview a part of the southern platform.
7. At the bus stop to the left of the terminal you can oversee most of the southern platform through the fence.
8. There is a small sandpath from the main road if you take the southern exit at the second roundabout from the airport. This sandpath leads to the end of the runway where you are slightly elevated compared to the runway.
I hope the above helps for future visits to this airport. Expect a lot of Ryanair, holiday charters and some bizjets. It is not a busy airport so ideal for a short visit.