Setting up a flagstone patio in sand is not a difficult project, except the stone can be heavy. When laying a flagstone patio, you should always use a back brace, gloves, and goggles. The stone used for laying a flagstone patio should be 2" thick. Since all of the flagstone pieces are a different shape, it is important to plan where each piece goes before setting it. It is essentially like putting a puzzle together. It is important to understand that the thicker and wider pieces will offer the most stability. When you lay the flagstone patio, make sure it is level with the ground to ensure no one trips over it.