Position the bulb so the top third is above the soil line.
When planting, by the way, set the crown of each plant just above the soil line.
The top of the root ball should be level with the soil line.
Ideally this bud will be about three to four inches above the soil line.
The union should be no higher than 1 to 2 inches above the final soil line.
This soil line must be maintained when the plant is set in its new home.
It doesn't matter if their noses stick a bit above the soil line.
As to the planting depth: look for a sign indicating the plant's soil line.
Not just glances, but pick the plants up, look under leaves and down at the soil line.
If one will do, cut the others off at the soil line.