Shovels, Picks & Hoes
Although it doesn't cross many people's minds to sharpen these items, having a good edge will make them much easier to use by cutting through dirt and plant matter with less effort.
A typical service is to sharpen only but surface cleanup / rust removal can be done also for an additional cost.
Methods will vary depending on the shape and overall condition. These include, hand files, hand held power tools or bench mounted grinders and linishers.