Sow deeply

Seed is covered deeply, which ensures that (a) the seed stays anchored while the radicle penetrates and (b) light does not reach the seed. Without adequate coverage, some seeds can be pushed clear of the surface as the seedling extends, leaving the roots exposed. I use fine chicken grit, because a thin layer is heavy enough to hold the seed down, and it is easy to spread evenly. If you don’t have access to fine chicken grit, a thicker layer of growing medium should work, though I have not compared the two directly.