31 year old transgender woman, 125 lbs. I wear butt pads to get the shape I want. How do I get it with plastic surgery? (Photo)

HelloThanks for the question and provided information as well. 

Based on your photo you are a good candidate for butt implants.
Buttock implants create a fuller, shapelier buttocks, helping patients
achieve better proportion and a beautiful body contour.

Depending on your preference, buttock implants can increase the size, roundness and projection.

I recommend you to make an appointment with a board plastic surgeon for a good evaluation and to talk about your goals.

Good luck :)

A consultation is necessary in order to determine the best size for you. I usually measure my patients and discuss desired results to decide which implant best fits their body and lifestyle.  Be sure to chose a Board Certified Plastic Surgery that specializes in Buttock augmentations and has extensive experience in performing these procedures.

 In my experience with very lean transgender women just like yourself, the only option for enhancing the buttock/pelvis area is intramuscular placed buttock implants +/- hip implants. Both implants are made of soft semi-solid silicone rubber which is considered to be relatively safe and permanent, unlike  breast implants that are made of silicone gel that can rupture and leak. Glad to be of help.