Farmer plowing in Germany. Photo: Ralf Roletschek
My first tilling tip: Unless it is absolutely necessary, don't till. Sheet composting, no-till gardening, heavy mulching, and other methods can usually prevent the need for tilling large areas.
The belief that tilling was necessary started in the 18th century with Jethro Tull (the farmer, not the rock band) who believed that plants physically ate soil particles. He taught that pulverizing the soil freed up nutrients for the plants to eat. We now know he was wrong, but his beliefs spread widely, and many books and gardeners still advise pulverizing the soil before planting.
The only time I recommend tilling is when a large area needs to have organic material added, the surface must be leveled, or a crop of green manure is ready to be turned under.
My second tilling tip: Take the time to do a thorough job. Inadequate tilling will lead to an uneven layer of uncultivated soil under the loose dirt on top, like an uneven floor under carpet. You can rake the loose dirt level, but as it settles with time and watering the uneven sub-surface eventually shows up as small hills and valleys. The uneven surface is annoying in a garden, but you can correct it next year. Correcting after a lawn is established is not easy, and mowing a bumpy lawn leaves thick spots and bald patches. If you are tilling for a lawn, you have one chance to get it right before you plant.
The most common cause of uneven tilling is trying to save time by tilling to the full depth of the tines on the first pass. Every time the tiller lurches, it leaves a high spot in the sub-surface layer.
Instead of trying to cultivate to the full depth of 8-12 inches all at once, make multiple passes across an area, lowering the blade a couple of inches each time.
Each time you lower the blade to cultivate deeper, start cultivating in a different direction and start half a row offset from the previous rows. Repeating the pattern and following your previous rows tends to make ruts that will show up later.
My third tilling tip: Make four - yes, I said FOUR - passes across the area at each blade depth. The first two passes cultivate the soil lengthwise and crosswise. Then make the third pass diagonally to the first two, and the fourth pass at right angles to the third one.
To incorporate extra material into the soil - compost, manure or sand - spread the material evenly over the soil and then till the area in the four directions.
My fourth tilling tip: Sharpen the tines before you start tilling. Before you lower the blades to till deeper, check the tines and sharpen them if they need it.