Visit your nearest garden supply store to find a decent selection of boulders that you can purchase. Always keep in mind that boulders are extremely heavy and will require special transportation and handling which might cost significantly.
Develop landscaping plan:
Make a landscaping plan which will include the exact place you want to place your boulders around the garden. Remember that boulders are difficult to move around so make sure that your plan is complete as it will be hard to keep moving things around.
Decide on setting style:
You will have to decide on the different style of settings for your boulders. Colour coordinating or laying them out by size and overall shape can also be a creative idea. The best way is usually to give a natural setting to your landscaping which makes it easier to place the boulders.
Now that you have a plan and decided on the setting style you can start placing your boulders around the garden. Since the boulders are really heavy it is good idea to use a truck that has a winch or hoist on it to help. This will save you a lot of time and energy as the truck definitely has the power to easily move the boulders effectively.
Keep open spaces:
Be sure that you keep some space open in your garden that is free from boulders. This is always a good idea as you might want to move something large in the future and the boulders will not be in your way while doing so.
Try to make effective use of plants to complement the boulders that you are using around the garden. Boulders provide a nice natural contrast when it comes landscaping, so try to use this to your advantage when placing plants around them.
You can also add some nice lights near the boulders to provide a beautiful setting when the sun goes down. However, water sometimes gets trapped under these boulders so be careful when working with any electricity in this area.