I usually speak to neighbouring landowners to find out exactly who owns the land I want to shoot on, and more importantly, the exact layout of the land. I then print out a map which has the potential shoot on it.
I began shooting on a small, family owned field but now I have shooting on adjacent land owned by four different owners. Its good to shade in the land you have access to so the next person can see how much ground you have.
I actually apprached a guy yesterday about shooting on his land. I previously had a large area shaped like three quadrants of a rectangle and his ground would neatly finish my shoot off.
I showed him my map with the other areas shaded, explained to him the amount of rabbits he had on his land. He told me to go ahead and take out as many as I could, result!
Try and explain to the landowner that you are using a non FAC airgun (I'm assuming you are) as this may sway their decision.
You gotta cold call to get a shoot, simple as that. I was nervous as hell when I went to speak to the guy yesterday, last night I went into his ground and found a serious rabbit problem. Fortunately the terrain is almost custom designed for airgunning. There is a long line of whins which have been cut down and stacked up in a line going down a hill. I can crawl up and down this line and snipe over or through the whins at the rabbits that lounge about in the evening sun. Absolute bliss.
Good luck,
Sub Sea Sniper
. . .and in that lair of the Deep Ones we shall dwell amidst wonder and glory for ever.