Always in a Cliff

Every time I need or want a particular item, such as an indian feather or spot a singing log, its always in a cliff where I cant get it.
Is it possible to dig on the cliff to lower it until its flat so I can get the item it greedly holds?
Iv tried digging on a cliff once before and the texture of the ground changed to dirt and it looked smooth, but despite that it still acted like a cliff.
On a somewhat related note, when I try to dig up some clay or limestone it tells me the area it too steep, can I dig this area out a bit so it isnt so steep?
Is it possible to dig on the cliff to lower it until its flat so I can get the item it greedly holds?
Iv tried digging on a cliff once before and the texture of the ground changed to dirt and it looked smooth, but despite that it still acted like a cliff.
On a somewhat related note, when I try to dig up some clay or limestone it tells me the area it too steep, can I dig this area out a bit so it isnt so steep?