Whether this is a private thing at home, part of your gender, or something you do for a night out, the practical questions are the same. Here they are answered plainly, without any assumptions about who you are or why you are here.
A note before the practical bit
People arrive at this for very different reasons — some as an expression of gender, some as a kink, some out of plain curiosity, some all three at different times. None of those needs justifying, and none of them changes the advice below.
If you are working out what this means for you, that is allowed to take years. You do not owe anyone a conclusion.
Shapewear and silhouette
Silhouette does more work than any single garment. Hip and bum padding creates the waist-to-hip ratio that most feminine clothing is cut for, and does more for how an outfit sits than the outfit does.
Options run from padded briefs, which are the easiest starting point and invisible under most clothes, up to full padded shapewear. Start with padded briefs — they are cheap, forgiving, and tell you quickly whether you want more.
Corsets and waist cinchers work, but should be sized properly and worn for limited stretches. Do not lace tightly the first time, and never sleep in one.
Breast forms
Three broad types. Air-filled forms are light, cheap and good for occasional wear, though they move differently to real tissue. Silicone forms are heavier, hang naturally and look convincing, and cost accordingly. Foam inserts in a padded bra are the cheapest entry point and fine under a thick top.
Size to your frame rather than to an aspiration. Forms that are too large for your ribcage read as costume rather than shape, and they are uncomfortable to wear for a full evening.
Adhesive forms need clean, oil-free skin. Do a patch test — adhesive reactions are common and unpleasant.
Tucking, done safely
Tucking gear — gaffs and tucking underwear — is designed to hold a flat front without the improvised methods people often try first.
Some real safety notes. Do not use tape directly on genital skin; it tears skin on removal and causes infections. Do not tuck testicles into the inguinal canal unless you have researched it properly and understand the risks. Do not tuck for extended periods, sleep tucked, or tuck while exercising. If anything feels painful, numb, or cold, untuck immediately.
Purpose-made gaffs exist because the DIY alternatives cause genuine injuries. Use them.
Lingerie sizing
Adult lingerie sizes run small and are cut for a different frame. As a rough starting point, size up one to two sizes from your usual clothing size, and measure rather than guess — our lingerie fit guide covers the three measurements you need.
Practical fit issues to expect: shoulder width and arm length are the usual problems with sleeved items, and back closures are the usual problem with bras. Look for adjustable straps, several rows of hooks, and stretch panels.
Packing, for the other direction
Packers are soft prosthetics worn for a masculine front. Soft-pack versions are for everyday wear and comfort; firmer versions exist for other purposes. Look for medical-grade silicone, and a harness or packing underwear rather than relying on tight briefs, which is uncomfortable and unreliable.
Buying discreetly
Everything ships in plain unbranded packaging with a neutral sender, and the billing descriptor does not mention what was ordered. If you share a household and a parcel arriving is the concern rather than the parcel itself, a workplace or collection point address solves it.
Where to start, concretely
If you want one purchase rather than a wardrobe: padded briefs, a simple bodysuit or slip in a stretch fabric, and a gaff if tucking matters to you. That combination costs very little, works together, and tells you far more about what you actually want than reading does.