Male to Female MTF : Estrogen ingestion causes nipples & breasts to grow. Chemical suppression of testosterone (puberty).

Female to Male FTM : Testosterone ingestion causes the growth of facial hair and it deepens the voice. Testosterone redistributes body fat (less) and muscle tissue (more).

Listen to a female voice change over a year on testosterone. This is irreversible.

This is yet often enough to be able to sell the illusion of being the opposite gender. We are trained to think "it's a man", when we see facial hair (beard) and to think "it's a woman", when we see breasts. 

Read more about the physical effects of Hormone Therapy here

Body Posture

Body posture, posing is a common obfuscation technique to hide the original characteristics: small or large shoulders, thin or thick neck and short or long arms.
Putting the Hands in the pockets to obscure the wide or narrow hips.

The MTF have a special way to walk, to dress. They will often employ misdirection to prevent you from noticing their typical male characteristics. 

A curved body pose to pretend there were hips, where actually none are. 

Scarves & Hair

Scarves, hair, jewellry, fashion, ... used to obfuscate the real width and form of neck & shoulders. Distraction.

Fashion & Make-up

The goal is to hide the large shoulders, small pelvis and V-shape upper body.

Trans Deception Accessories:

Hip pads, Camel Toe slips, ... to look like a woman. A lookalike, a fake women. Biological men can never become real biological women, will never be able to give birth !

Fake Silicon Chests & Moonbumps

Tucking

Hiding the external genitalia. The intake of Estrogen can decrease the size of testicles & penis.