A lawn grows best on well drained medium loam, if your soil is like this, your preparation can be minimal, but if the soil is clay or sandy, you'll need to do more work. With heavy clay soils, you should add sharp sand, well decomposed manure, garden compost or rotted leaves.ry to build up as much ground as you level down, this will mean that you won't have much soil to dispose of. If the ground is levelled up by more that about a foot (30 cm), leave it to settle for a year before laying turf.