Lay a measuring tape or T-square along all edges of the floor, countertop, desk or other item that you intend to cover with laminate sheeting. Write down the measurements on a sheet of paper. Measure a second time and compare the measurements to what you have written down.
Lay the laminate on the floor, face up.
Measure the laminate sheeting to match the measurements you made in Step 1. Mark out the cut you're going to make with a grease pencil. Use the ruler to make straight, even lines. Mark long horizontal or vertical lines by measuring in from the edge of the laminate sheet. For example, if trimming 3 inches off of one side of the laminate sheeting, measure and mark the point 3 inches in from the edge with your T-square at roughly 6-inch intervals. Then draw a straight line, 3 inches from the edge of the laminate sheeting that connects the marks.
Measure the lines again to check for accuracy.
Move the laminate sheeting to a large work table, face up. Hang the edge you intend to cut off over the edge of the table.
Cut the laminate with a pair of scissors. Hold the main part of the laminate sheeting steady while you cut.
Wipe the edge with a rag to remove any cutting debris.