With low-voltage outdoor lighting, you can achieve a look that is natural, multidimensional and dramatic. A quick read-through of the following points will help you create designer-quality results when installing lighting yourself. But bear in mind that it is easier to add lighting than to take it away, so don’t overdo it.
As you make your low-voltage outdoor lighting plan, it's also useful to think about how long you plan to live in your current home. If this home is a short-term investment (2-5 years), you don’t want to over-improve with elaborate outdoor lighting. If you plan to be there for many years, then you should make improvements that will really satisfy you.
Lastly, take your skill level into account to determine how long your outdoor lighting installation will take. You need to gauge the degree of difficulty and compare it with your skills to understand what's involved in the installation.
Planning: First, be aware that you are installing low-voltage outdoor lighting and NOT line voltage. Low-voltage lighting is easy to install and safe to use. For line voltage, you need to meet national electric codes as well and have either the proper experience to install it or hire an electrician . For low-voltage, you need to know the state code for your installation. Once you know these parameters and you’ve mapped out what you want to do, you can begin.
Determine where you want the lights to go and where you’ll need to run wiring. This will help you figure out whether you can do the work with hand tools or will need special equipment to bore under concrete driveways  and pathways.
Always test the outlet you’ll be using for the transformer with a voltage meter so you know exactly how many volts you’re working with. This is very important, and a voltage meter can be purchased at any DIY retailer. Low voltage must be under 15v, and the most common is 12v. If you’re running at 120 to 125, you’re running low-voltage to 12v. Low-voltage is less expensive than line voltage and safer for the DIYer to install. The formula for determining voltage is as follows: watts x length¸ wire constant = voltage. If you are running at 15amps to 25amps, the new transformers will trip circuit breakers.
Transformers: You will need a transformer to run your low-voltage outdoor lighting. The best transformers are purchased from landscape lighting  suppliers and lighting distributors. It is very important to invest in a good transformer, and one of the biggest mistakes people make is to buy a transformer that’s underpowered, causing the voltage to drop off before reaching the outer limits of your outdoor lighting  design.
If you have to choose, spend more money on a good transformer and install fewer lamps. If you are on a restricted budget, start by lighting the front of your home first, and when you can, light the back areas and deck. Having a big enough transformer will allow this flexibility. Transformers usually provide 80 percent of the power that they are listed as having. For example, a 300v transformer offers a 240v return.
Use a stainless steel transformer box for outdoor installations to avoid rust and corrosion. All transformers need to be UL listed. The transformer can be placed in various locations and should be installed at least two feet above ground, especially for northern climates that receive extensive snow. You will need to use Schedule 80 conduit to install the transformer, which is available at any DIY store. If you install in an area where there is shrubbery, make sure you face the door of the transformer away from the bushes so you can access it easily as bushes grow.
It is also important to carefully label all wires running to the transformer. Make sure that as you do your splicing, you're keeping track of which wire goes where. When using cramp on installation, you want the wiring to have the shortest path possible to the transformer which is why you may need to go under concrete. The longer the wire from the transformer, the dimmer the light conductivity is.
Install: Before your install your low-voltage outdoor lighting, you need to check local code regulations for wiring. Overall, it is recommended that you bury wires 6 to 8 inches in the ground (most states require this). In southern climates, it is currently code to lay wiring under pine needle mulch, although this regulation may change. You will also need to know the soil type and locations of irrigation systems  before you begin.
The night before your low-voltage outdoor lighting installation, thoroughly wet the area where you will be digging. Wet soil is easier to work with than dry.
When you are ready to begin installing your low-voltage outdoor lighting, take your wires and fixtures and lay them out in the arrangement desired. This will create an above-ground map before you begin to dig. Once your lighting fixtures are positioned correctly, embed them into the ground.