Use wire that has more hookups than you need. Often times you will only have three or four different zones in your automatic sprinkler system. You will still want to use a multi-stranded wire that has more wires than you actually need, so that you will have room for expansion later or a spare wire to use in case of problems with one of the wires that you are using. A three zone system requires four wires to operate --- a common wire that runs to each sprinkler in series and a separate wire that runs individually to the zone valve. If you are using single-strand wire, this will not be a consideration for your system.
Dig a trench and make sure to run the wire deep enough underground to avoid problems. Generally, eight to 12 inches is the ideal depth for sprinkler wiring. This can be trenched in easily but is deep enough that a casual shovel or raking will not disturb the wiring. Too deep, and the wire may be difficult or costly to access in case of repairs. Too shallow, and the wire could be damaged by casual digging during landscaping, or even by lawn and garden equipment such as a lawn mower or other outdoor power equipment.
Run a test of your sprinkler system once it has all been correctly wired in order to be sure that all of the sprinklers operate when they are supposed to, as well as to make sure that all of the zones are correctly wired. Testing your wiring for errors before you bury the sprinklers and connections will make troubleshooting easier.