I've grown tomatoes for the past four years, and not beyond that, so my status is far from expert. But here's a few tips and tricks I've learned since then.
1. Spacing - you'll read about how far to space out tomatoes. I actually had the best success with my tomatoes closer than the recommended spacing. It happened on accident, at first, where I just slapped in some tomato seedlings I'd bought and had no idea how big they would be, or how far apart I was supposed to put them.
Shade cloth, or partial shade during the day, is usually recommended for tomatoes in the desert, but I didn't have almost any shade in my yard and didn't have the money to purchase much past the tomatoes themselves (plus their veggie neighbors).
It turns out that planting them close worked out amazingly well. The outside of the tomato plant was dry, not pretty, not going to give me much in the way of tomatoes. However, growing them so close together made what I think of as a tomato jungle, and the inner part of this jungle was shaded perfectly. I got masses of tomatoes from these plants, just on the inner sections. I've met a couple other gardeners here who have had the same experience.
So if you've got tomato seeds, planting them closer together to form, I dunno, a sort of micro-ecosystem, may work rather well. It sacrifices the outer edges of the plant, but I personally got enough tomatoes that it didn't really seem to affect it enough to be a negative.
2. Mulching - yes. Do this. A lot. I simply let the weedy native grass grow in my yard until it's big, then pull it and let it dry out, and use it for mulch. Or you could buy some yourself and add it. A few inches thick is a good idea, out here in the desert.
A lot of people here use rocks or gravel on top of their soil for water conservation, and I know some who even do it for their gardens, but when it really starts to get hot, this has never worked out for me. It radiates heat like a furnace and, in my yard at least, has fried the plants it's next to. Perhaps others have more success, especially underneath shaded areas where it keeps moisture in but has less sun exposure, but if you don't have shade or shade cloth, I wouldn't recommend it.
3. Rotating - if you are new to gardening, know that pretty much every gardening book I've ever read says to rotate tomatoes, or in layman's terms, don't grow them in the same spot year after year. Grow them in one spot, then move them. Some say just alternate years, some say to have a three year cycle of rotation. It's to let this nasty tomato-ey mold die off so it doesn't infect the next year's tomatoes. I haven't yet discovered what the most recent information on the life cycle of this mold is, so I follow the three year rule.
I have also read that this same mold can affect anything in the same family, the nightshade family, so avoiding planting peppers, eggplants, and potatoes in the same soil for the same amount of time is a good idea, too. I haven't researched it much, but I've seen that same type of mold develop on both my peppers and my tomatoes, so I'm willing to believe it without much more proof.
4. Support - this is tricky here in the desert. I know some people use metal. Sometimes that works, but sometimes, it gets so hot that it's damaging to the tomatoes, too. If you have some shade, that's not such an issue, but if you have no shade for your tomatoes, I would choose something other than plain metal, to be honest. I have saved medium sized branches that I trimmed off my trees to make supports for my tomatoes, as well as some bamboo poles I made into frames. The wood works, but can be problematic because we have enough native termites here that they will often take an interest. The bamboo works well, though, if you can afford it.
5. The summer - if you have tomato plants that keep producing for a long time, they usually will stop producing once it gets too hot. However, if you can keep them alive through the summer, a lot of times they will make you some more tomatoes when it cools a little, before the winter hits. So you may not want to give up on them as soon as they wilt in the heat. :-)
6. Pollination in the Heat - above 90 F during the day and 75F at night, consistently. Tomato blossoms won't open, the high heat will destroy the pollen, and new fruit won't set. So basically, your tomatoes can't pollinate once the heat gets too high.
A tip for dealing with this that I have heard is to go out in the morning, before the heat builds, and gently shake the tomato plant, like the wind would. That way, you can spread a little of the pollen from any open flowers, before the heat destroys them. I don't know if this works well, but it's worth a try.
Another possibility may be to have some of the tomato plant in fuller shade. The pollen in fuller shade might remain viable and able to be spread to the other flowers in the heat before the pollen is destroyed. I have also had better luck with my tomatoes that had solid shade for part of the plant, such as from a wall.
And lastly, try to get local seeds, from tomatoes that have been doing well here for longer periods. In the Sonoran Desert, some of the local libraries have started up a Seed Lending Library in the hopes of developing more drought resistant seeds for our desert growing, and Native Seed Search has tomato varieties that have been grown here for a LONG time.
7. Dryland Farming - 4. Sadly, this one is pretty much a bust, here. You need somewhere that gets at least 20 inches of rain a year (we're closer to 12) and has soil that retains water fairly well. If you have a lot of soil amendments and you supplement watering a little, however, you might be able to approximate it. This company sells seeds that have done well being dry farmed: http://sustainableseedco.com/dry-farmed-tomatoes/
This page talks a little about how to do it, although we need to adjust for seasonal differences: http://www.sfgate.com/homeandgarden/goldengategardener/article/Dry-farmed-tomatoes-how-to-grow-them-3169535.php
A good tomato resource: