How Do I Get a Rounder and Butt Shape Like Girls?

             Depending upon your anatomy and goals, buttock implants or fat transfer to the buttocks may be appropriate.   Find a plastic surgeon with ELITE credentials who performs hundreds of Brazilian buttlifts each year.  Then look at the plastic surgeon's website before and after photo galleries to get a sense of who can deliver the results.

Kenneth Hughes, MD Los Angeles, CA

Hello dear!!
Thanks for the question and provided information as well. 
You can probably benefit from a BBL, to give you a nice round buttocks. Unfortunately, without pictures, it is very difficult to give you a proper answer. 
In general, you need to be physically healthy and at a stable weight, have realistic expectations, be a non-smoker and your BMI needs to be 30 or less. l recommend you to make an appointment with a board certified plastic surgeon to talk about your goals and anything you need to know.
Good luck :)

Allow me to share with you some information that you may not hear elsewhere. There are only two proven safe and relatively effective methods for Buttock Augmentation and Hip Augmentation: 1) Autologous Fat Transfer (using your own fat, transferring from one area of the body to the other) and 2) Buttock/Hip Implants (semi-solid silicone rubber implants that cannot rupture &/or leak). Both are very good options so what it comes down to, like any surgery, is proper patient selection. Indeed because at least 50+ % of the fat transferred will melt away within a year, most patients are not good candidates because they lack an adequate amount of fat to harvest. Another tip is that if you gain weight for the procedure, the fat that you lose first when you go back down to your baseline weight after surgery is in fact that fat that you originally gained and transferred into your buttocks...so don't fall victim to this recommendation.  Although using your own fat is relatively safe, the one serious complication that can rarely (< 1%) happen is "fat embolism" in which some of the fat gets into the blood stream and travels up into the lungs, heart, and/or brain causing serious problems. This complication is more likely to happen with the larger amount of fat being transferred. This can also happen when using fillers like PMMA and hyaluronic acids. Also fillers, when injected in large quantities, have a relatively high tendency to migrate away from the original area they were placed and tend to stimulate a lot of inflammation and subsequent scar tissue/hardening.
Thus buttock/hip implants become a very good, safe, and long term reliable option for most patients seeking buttock augmentation (at least in my practice). I prefer to insert the buttock implants through a single 2 ½ inch long incision over the tailbone (concealed within the crevice between the buttock cheeks) and the hip implants through a ~ 1 inch incision just below the beltline above the hip region. The buttock implant should always be placed under or within the gluteus maximus muscle. In this position, the implant is less palpable, less visible, and does not sag or shift/migrate over time unlike implants placed on top of the muscle. Therefore it is extremely important to seek consultation with a board certified plastic surgeon who specializes in this procedure. And in this case too, at least in my surgical practice, the infection rate is minimized to ~5%. Glad to help…