I recently bought an ergonomic toe nail clipper. The large anti-slip surface ensures that I clip instead of slip. (There are even long-handled toe clippers available, but you may want to sit down when you check the price.)
While I’m on this topic . . . it’s important to keep your toe nails short, especially if the tips of your toes curl under. Each step you take may be putting pressure on the nail, resulting in unnecessary pain.
Related post: Pretty, Pretty . . . Nails.