The most common causes of toes crossing over and even toe deformity is because of shoes that don't fit well or even high heels.
When you wear high heels you increase the pressure on the ball of your foot which leads to injuring the stabilizing structures of your toe.
Other causes of an overlapping toe are due to problems with bunions that already exist.
Surgery is about the only thing you can really do to actually fix an overlapping toe and wear broad toe boxed shoes that allow room for your toes.
Other than that you can try a few other things such as Gently pulling on your toes to stretch the bent joints.
For example, if a joint bends up, gently stretch it down.
Do towel curls. Put a towel flat under your feet and use your toes to crumple it.
Do marble pickups
Although those can help with overlapping toes surgery is the only 100% way of fixing overlapping toes.