If you live in the northeastern United States and garden, one thing you almost certainly will deal with is rock. One technique I found that works quite well for dealing with this problem is at first glance, perhaps, rather surprising.
Here it is: if you are planting a shrub or tree of any size,
plant where there is a big rock. Why? Well, once you dig out that one big rock, you have a rather nice hole to plant in. On the other hand, if there's no big rock there, and your yard is anything like the places I have gardened, there will be lots and lots of small rocks. Believe me on this: it is a lot easier to get out that one big rock than all of those small rocks.