There are a number of factors which determine the quality of a lawn especially in a dry climate. Correct irrigation, an appropriate feeding regime, regular mowing at the suitable height, are all basic requirements. With grasses that produce a heavy thatch, an annual scarifying job is essential, and top dressing the surface with sand (sometimes mixed with compost) is often necessary to straighten out the bumps and troughs in a lawn. However today I'm going to focus on a number of steps which are sometimes overlooked but should be taken before you lay the turf.

Make sure of adequate drainage. While grasses require a lot of water, their roots require a sufficient percentage of oxygen in order to breathe. A good if rough method of checking the drainage is to dig holes about 50 * 50 * 50cm, fill them with water and see how long it takes for the water to drain away. Up to three hours is generally reasonable, more than a day is untenable.
Improve the soil with a generous quantity of well rotted compost. I use about 30 liters per square meter. Then incorporate the compost into the soil with a garden fork or mechanical rotivator. Obviously you're going to rake the soil until it's smooth and straight before laying the turf.

But there's a little secret that can often make all the difference. It's a secret that's especially relevant to small lawns and therefore to those in dry climates where the size of the lawn should be kept to a minimum.

The smaller the lawn, the more the soil underneath is liable to get compacted, due to the high amount of traffic relative to the lawn's area. Soil compaction, with the resultant reduction of gas exchange and water infiltration, is one of the major factors in lawn failure. While compaction under an existing lawn can be relieved to an extent by aeration, it's a million times better to prevent it in the first place, by insulating the soil from the impact of traffic. This can be done by spreading about 10 cm of sand or some other inert material, between the soil surface and the turf. That's how it's possible to have grassed parking lots!

WARNING: The sand must be leached of salts.
Laying an insulating layer can be quite expensive, because in addition to the material itself, you may have to excavate a lot of soil. However, I cannot think of a surer way of bypassing the problem of soil compaction, and assuming that the other factors are taken care of, giving you a much better chance of having an excellent lawn.