My daughter is fascinated with all things "medical" because we have some doctors in the family. She is always trying to "doctor" us, so I decided she needed a lab coat to go with her doctor bag:
I simply purchased a white collared button-down long-sleeved shirt for $2 from Goodwill. After a GOOD washing in some bleach and ironing after drying, I measured my daughter's arm length from her collar bone to her wrist and added an inch for hems. I transferred the measurement to the shirt sleeves, lopped them off at the mark, and hemmed them.
Then I used the left over sleeves to make 2 pockets for the front (bottom) of the lab coat. I pinned and hemmed the pockets first, then pinned and sewed them to the shirt, leaving the top of the pocket open (duh!). I then added large buttons down the front (for affect) and velcro to the inside placket (for ease of child play). A plastic name tag (on-hand) completes the look. Can't beat $2!
***I am NOT LIABLE for any plans featured here. Please take every precaution and use your own discretion to make sure these toys are safe for children to play with them.