As I said previously, I have no expertise at producing these charts but, until an expert comes along and puts us both right:
If your helicopter has a vertical procedure (and I note that you have referred to an EC135 in earlier posts) you could:
1. establish the rejected take-off distance required. Superimpose that on your site to see in which directions you can depart/arrive.
2. establish that you meet the criteria for the clear area in the back-up direction (it will be in the FM but, if it is not, see the guidance in JAR-OPS 3).
3. establish the 'take-off distance available', in the direction of departure (a clear area with no obstacles):
a. if that is within the take-off distance required (from the FM) then stop there; or
b. if it is insufficient, establish the highest obstacle in the continued take-off add 35ft and set that as your min-dip and note the take-off distance required.
4. from the TODRH measure the departure angle in the departure direction and check that there is a 1D plus 10% divergence on either side of the departure path (to a max of 7 rotor diameters).
See how many of these clear departure paths you have and choose the best.
Mark them on a aerial photo ensuring that you mark the TODRH circle (it should be the same for all departures)
Mark all significant obstacles (those which penetrate the departure surface).
See how it looks and then decide whether you wish to do it in anger.
Jim