I start out trying to push the stake in by hand. If that fails, I move the stake a few inches and try again. If I need to use a rock, I rarely use it to pound. I use it to push as much as possible. The rock just saves my hand from bruising by spreading out the pressure point on my hand.

Pounding only seems to work in material that is packed hard together, but not solid, such as close-packed gravel. If your stake has met a solid rock or a big root, pounding it will only bend or break it.