How will I know my child is ready for potty training? Are there any signs?

Some signs you can look out for include: 1) You are changing lesser diapers than usual 2) Baby's bowel movements are quite regular 3) My friend's baby started hiking her skirt or shirt up each time she pooped in her diaper. My friend realised that her baby is imitating her actions whenever mommy goes potty herself. My friend decided that baby is ready to be potty trained after noticing that.