Shins; just find something Youvan practice on that's semi hard. Some people in Thailand practice on bamboo. Fists; find the parts of the walls in your house where they're a little bit denser and punch them hard enough you feel it after. I've been doing this for a while, lately I've been practicing on the stucco on the outside of the house, it's a little bit different though cuz it's sharper. Also, try not wearing gloves during drills if you already do.