Princes Risborough is the usual pre-arrival reporting point when approaching Wycombe Air Park from the North. You can of course join from any direction but these landmarks will make ATC's instructions to you easier to follow.
Princes Risborough can be recognised by several quite clear features. The five railway lines and the proximity of the hills on the Eastern edge make a unique pattern. On the side of the hill is a (now not very) white cross which further helps identification. Provided you have found Princes Risborough all you need to do is follow the Southbound valley which takes you towards the Golden Ball monument and the airfield.
The keen-eyed pilot will notice that Wendover (only four miles North East of Risborough) also has railway lines and a valley.
Mis-identification here could create two problems: Wendover is inside the ATZ of Halton and the valley from here takes you not to Booker, but to Heathrow. Beware, it has been done!!
Make sure that you identify the correct railway line from Risborough to the field. The "loop" shown here is a good clue.