If your foot is well supported in your shoe, without internal movement, but you still get hotspots, then lubricating cream or foot powder can help reduce the friction that causes blisters.
If you’ve never got on with plasters, smearing a waxy coating on your foot before a long trail run can help avoid blisters. Alternative? Clean, dry sheep wool in your sock (don’t wash – this removes the lubricative lanolin).
Preventing blisters caused by friction.
Don’t like plasters? Try this. You’ll be impressed.