We have a rather binding, clayey and/or loamy soil that we had distributed on the land after the construction using a mini excavator, not large equipment; doing it by hand would have been even better. We moved in in September and initially decided to plant only some shrubs and a hornbeam hedge for the winter, but to sow the lawn only in spring. First, we let the weeds grow; there was still a lot of rapeseed in the soil since the construction site had formerly been a rapeseed field. The growth was treated once with glyphosate. Clean. Shrubs planted; after glyphosate, wait at least 48 hours, then you can work the land again. The soil was broken up with a Rhenish hoe and made crumbly with a grubber. Winter. In spring, it was hoed and grubbed again. Lawn planted, no topsoil applied, only some sand worked in here and there. The lawn now needed a starter. Given wheat fertilizer once, mineral-based, with a spreader. Then it took off like a bat out of hell. Started mowing with a mulching mower. Through the mulching mower, signs of soil life soon appeared, worms and such. Now, after 18 months under grass, a good humus layer has formed; I have repeated fertilizing with wheat fertilizer, which consists of nitrogen (N), magnesium (Mg), some sulfur and phosphorus, and contains some potassium, about every six weeks; meanwhile, it fertilizes itself through mulching mowing. Thus, fertilizer applications have become more sparing. Since clayey soil is slightly acidic, the land received a garden lime treatment in March this year. Check YouTube on how to do it. Use slaked lime; unslaked lime is too dangerous, it burns plants too easily. The hornbeam hedge and all shrubs and bushes have taken well; they also always got some fertilizer. K.