When I am looking for airfields I look for a light coloured or green expanse of land in the general direction of the AD, obviously this is no use when locating a grass strip amongst fields but is usefull when locating hard surfaced runways. Also if it has been raining, hard runways reflect very well.
Also, when you know which runway you are going to be landing on, look at the DI and try to imagine the runway orientation in relation to it and the terrain below. Sounds complex but works really well.
Happy New Year all and Fly safely.
Regards, Trislander