I challenge you to photographs shoes that people are wearing while they are are walking or standing in the streets. This exercise requires you to go out and have your camera ready at all times. What kind of f-stop are you using, what exposure time and ISO setting? Try different setting and study the results.
I started out photographing at crossings. People were standing and waiting for the green light. that gave me plenty of time to compose my shot.
Enjoy and keep on photographing!