, there is a road that runs round the perimiter of the airport. To get to it, go from the roundabout by the terminal down into lulsgate, and turn into the first road on the left. Follow it until you get to the signs for the golf course and flying club, and turn left up there. It comes out at a fence which is right beside the taxiway where you can get 19mm sideon shots of aircraft taxying past, or you can follow the road round to the other side where you get good rotate shots/touchdown depending on the winds. Otherwise, there is somewhere to stop at the roundabout for the long stay car park, on the entrance road there although you might get moved on, and its quite a way from the runway.
There's a path that runs down to the threshold there but i'm not sure whether you are allowed to walk down there, you get arguably the best view of the action but you could get told off! You can also see from the staff car park but you might get moved there. There's one last place thaT I usually visit thats quite hard to get to, you used to be able to go into the field with the approach lights by the A38 but i've been moved from there almost immediately as it is apparently airport property. However there is a common behind it that you are allowed to view from, but its quite difficult to get to. It gives you a pretty good view of the apron and aircraft taxying to 27, but is quite far away. You get a reasonable view down the runway but there is stuff in the way.
If you want to go there I can tell you, but its a bit more difficult.