Step 1
Measure out the location in the yard where you will be using the timbers.
Step 2
Mark the timbers where the cuts will need to be made. Be as efficient as possible when choosing the length of each timber so that as much wood as possible is usable after cutting.
Step 3
Cut each timber individually. If you're using neater wood that has been sanded or pressure treated, set the timber on the sawhorses and clamp it in place. Use the circular saw to make the appropriate cut. Depending on the size of the timber, you may need to rotate the timber and make a cut on each side.
Step 4
Use a chain saw for rough-hewn timbers or railroad ties. Wear safety glasses and gloves for this sort of cut. You'll measure out your cuts the same, but leave the timber on the ground for cutting.
Step 5
Make your cut very slowly if you're using a chain saw, especially with railroad ties, which sometimes have nails, rocks or other hard objects embedded in them.
Step 6
Smooth the cut edge with a file or fine-toothed saw if necessary. This probably won't be necessary with a circular saw cut, but it may be needed with a chain saw cut.