I am currently trying to create a more defined waist for myself,I would do anything for that hour glass figure

I am currently 5 feet 2 inches tall and I weigh 150 lbs. I just had a baby 5 months ago. I would like to lost around 40 lbs by the end of this year, but right now my main goal is to create a more defined waist for myself. I would just do anything for that hour glass figure. Any suggestions and/or comments are all welcomed. Thank You