Drying your own wood, whether for woodworking, carving or turning, can be very rewarding--if you can keep it from splitting. Wood loses moisture from the ends at a higher rate than the faces and sides. While you'll never stop wood from losing moisture, you can slow it down enough to prevent splits and cracks (also known as checking) from forming. The key is to seal the ends of the boards before drying. Many commercial solutions are available, but a few cheaper and more readily available alternatives exist.
Mix a solution of equal parts of the aluminum paint and spar varnish in a plastic bucket for large slabs or logs. It's important to coat all the ends at the same time because if you treat only part of the lumber and then come back to the rest later, your lumber will not dry at the same rate.
Paint the solution on the ends of the large slabs or logs with the 2-inch brush. Wear rubber gloves to prevent any aluminum paint from getting on your hands. Cover the ends thoroughly. If you see the solution soaking in to the end grain, keep painting it on. Use two coats on each end.
Mix a solution of equal parts white wood glue and warm water in a plastic bucket to seal the ends of smaller boards or small logs. This will soak in to the ends a lot more, so mix plenty of it.
Dip a clean 2-inch disposable brush in to the glue solution and paint the ends of each board or log. Keep painting it on until it stops soaking in.