The tripod is an essential item. Its use will dramatically improve your photos. Never leave home without it. Tripods allow you two basic improvements. The first one is a sharper focus and the second one is a better composed image.
Blurred images are caused by camera shake and a rock solid tripod helps eliminate this camera movement. Your photos will suddenly be improved with a sharper focused image. Also you can shoot in low light conditions and take advantage of lower ISO speeds and smaller aperture settings.
Using a tripod causes you to slow down and improve your compositions. You can get a closer look at your shot. Fine adjustments are now possible. You can even wait out a lighting change as a cloud passes overhead or a wind ruffling the leaves and grass. The tripod gives you time to evaluate the subject and its environment.