1)Add some to the bath for a relaxing soak for soar muscles. I think this is probably the most common use.
2)On itchy skin or for bug bites: Dissolve a tablespoon of epsom salt in 1/2 cup of water, let it cool, and then spritz it on itchy skin or soak a cloth in it to make a soothing compress.
3)In the garden: Adding a few bags to the soil before planting can help replenish the magnesium levels in the soil, which have been depleted due to over-farming.
Do It And How 