In the above diagram, please not the depths, which may vary depending on the type of project you are doing and your soil. Before you start have a good plan, and you can't go wrong. What type of path do you want to create, what type of driveway or patio are you seeking. Draw your idea on paper and scale it down. Use pencil so you can play around with your design until you have perfected it.
Make sure in your plans that your project has adequate drainage, this will keep your path safe and durable. Also if you path is going to be near any building structures make sure it has a slope away from the structure. The slope should be 1/8" per linear foot.
Most times for paths, creative designs are made. You have so many choices of pavers to choose from. Most being brick or concrete. There are many sizes, shapes and colors to choose, just find the style that best fit's your liking.
If your path is a common design you can calculate by measuring the square footage of the footprint by adding five percent. If the designs have alot of curves you should get ten percent over your square footage estimate. Always get extra because you will need some to cut. If you want to get fancy, you will more pavers that will have to be cut.
Outline the project area. Use string or garden hose to outline your project. Drive stakes to hold the outline in place and to make clean corners.
Your slope should be a little above your surface surrounding the ground at all points. When you plan your slope, start at what will be the highest point. This is usually the point at the bottom of the front door. Drive the first stake at your high point, and make a mark for the correct height where your pavers will meet the door. It is best to tie a string around the stake at that height. Next you will want to drive a stake at the outer boundary. This is the lowest point. Then attach a line level to the string, tie the loose end of the string to the outer stake at it's height at which the line level states. From that line you will move down the stake 1/8" per linear foot. If it is 8 feet from your front door to the outer edge move the stake 1", and draw a new line. You will then move your string down this line. Then string cross lines down the length of your project, this is to mark the correct depth across your entire project. With a project that has a variety of slopes, or if your design is irregular, repeat this step at several points. The slope is very critical, so the more you stake the better.
Make sure you measure your depth frequently. Always measure from the line, not the surface. Spaces will be exposed only to the foot traffic which you need 4 to 6" base material. Driveways and projects that are in wet soil will need 12" of base. If you need help figuring your base you local building supply store will help you. But make sure you add 1 to 1.5" for the sand layer, plum the thickness of the pavers. This will depend on the brand you use and the style. The typical base is 2 3/8 or 3 1/8. Your sum of depth of the base, sand and pavers will be how deep you'll need to excavate your projected area. Excavate 6 to 12" beyond the boundaries of your project to give enough space for your edge restraints. The depth of the excavation from your string will track your slope but not from the ground surface.
You will use a plate compactor for compacting the base. Your base material is crushed stone with sharp edges. Add no more than 2" at any time to your excavated area than compact. It is important your area is very well compacted. This process is repeated until your base is the correct depth. This will be your last chance to adjust the height of your project, and make sure you don't have any dips, or bumps. Increase or decrease your thickness of the base as it is needed. But make sure you make frequent measurements from your string base.
Outside boundaries will make your project more stable. You will install your edge restraints and secure them with landscaping spikes. These restraints will hold your projects shape for many years. The restraints are usually plastic, aluminum or even steel. The restraints will have to be cut in order to follow your pattern.
The sand is your glue for your project. It will need to be smooth to a depth of 1 to 1.5" but no more. For projects that are on the large side, you will want to lay 1" screed pipes, then pour the sand in between the pipes, in small sections of 50 to 100sq feet each. Then remove the pipes and fill in the gaps with more sand.
Next it's time to lay your pavers. This is really the easy part. Start laying pavers at a 90 degree corner. Usually at the abut of the structure. You can work from there, working your pavers in a straight line. Lay them in the sand do not slide them or kick them into place, because you don't want to disrupt the sand. Slide each one straight down the edge of the adjacent paver. You don't have to worry about gaps. Usually you want to have a gap of 1/16 between each pavers. Every so often make sure the pavers are level. You can do a string check. Keep your lines straight and work from the top of the pavers you have installed already. You probably have to cut some pavers for your edges. Don't try to curve your pavers to fit your edging. Lay your pavers than do your cutting. Make sure you do not step on your sand. Use the pavers you have laid so far. But don't step on ones near the edges this can disturb the sand. You can also seal your pavers with a sealer.