Sharpen a shovel
Your shovel will slice through dirt and roots easier if it has a sharp edge. If the point of your shovel is ragged with dents or chips, start by smoothing it with a grinder (Photo 1). Then switch to a mill bastard file (Photo 2) to file a bevel. You don't want a knifelike edge. Instead just bevel the top edge at a 70-degree angle to the back. That's pretty blunt compared with the 25- or 30-degree angle used for knife sharpening.