The humble compost sifter (also called a "compost screen" or "screener") is a valuable tool for gardeners. It is easy to construct one or several for use around the garden.
The classic sifter is constructed from 2X4s, with 1/4" or 5/16" galvanized square metal mesh (usually called "hardware cloth".) Large sifters can handle shovelsful of material; smaller, "trowel-sized" sifters are easier to move around. Wider-mesh screens up to 1/2" may be used for coarser results; window screen is too fine to sift through.
Hardware cloth attaches readily to stud lumber with a staple gun; light nails or hammered U-nails may also be used. Covering the attachments with a strip of lathing, 1x2, or molding will strengthen the sifter, protect fingers from catching on the edges of the hardware cloth, and generally extend the life of the sifter.
A rectangular larger sifter may be propped up at an angle against a bench or other support to allow gravity to aid in the sifting -- the material slides down along the mesh and sifts as it goes. The best angle for this is around 30 degrees. Some sifter designs have a folding prop built-in.
Another useful design tip is to size the sifter so it fits nicely over the top of your wheelbarrow, with downward edges to hold it in place. This allows you to sift directly into the barrow for easy transport elsewhere. (A simple ramp or small hill of earth can place the whole wheelbarrow at an angle to let gravity help with the sifting.) A similar design for smaller square sifters fits over plastic buckets. Another design fits the screen within the wheelbarrow or container, with rails or handles keeping it in place.
Sifters may also be suspended by rope or chains (one to each corner) from an overhead frame; these "shaker frames" allow for the handling of large amounts of material, may be designed to be moved as needed, are more efficient, and are easier on the back of the operator. A simple tripod of scavenged poles, lashed together near the top, makes an easily-moved support from which to hang the shaker screen; the height of the screen can allow sifting directly into a wheelbarrow below.
Material too large to fit through the mesh can be put in with fresh compostables to continue working, or used for mulch.
A well-built sifter, braced at the corners, should last for many years of use around the garden. The sifter is also generally useful around the garden, as a tool for filtering gravel and roots from planting soil.
NOTE: The points on trimmed hardware cloth can be sharp. Trim very close to leave no point, trim long and then bend back, or apply a strip of wood (like a 1X2) along the bottom edge of the sifter where the hardware cloth is attached. This strip not only covers the edges of the hardware cloth, but can serve as a lip to hold the sifter onto a wheelbarrow or bucket.