I use bulb tone for new planting as directed on the package plant at appropriate depth and water in. Some soil will settle usually and I often end up adding a bit more soil to be sure I have the correct depth.
The year we had a severe drought and I planted peonies that fall,I received some planting advice from Roger Anderson: to dig the hole and soak the hole with water until the surrounding soil was very moist, then plant to correct depth and water in. The plantings all did very well that next season despite our horrible growing year the year prior. I chose to plant every peony I received that drought year that same way. Now when I plant,if things seem dry at all I soak the hole, wait to it to absorb in the surrounding soils and then continue planting.