I just purchased my first bras, a couple cheap racerback sports bras, the plan is to use them to try to hide breast growth for a while, I've already got close to a B cup before HRT from being overweight probably. Anyway, the bras I got fit well, my back feels so much better with it on, but I noticed the straps can sometimes be visible through the neck hole of my shirt, and wondered if there's a certain type that'll be a bit more discreet but still compress well, these ones make me pretty flat, which is what I wanted, but still leaves me feeling a little deflated, no pun intended. Ideally the bra straps would fall further away from the neck, but still line up with a tank top (undershirt, obviously not expecting a tank to hide a bra) for plausible deniability!

I have been wearing sports bras for the last month to hide the girls under my male disguise.  I got the type that resembles a men's tank top.  So, if anyone sees the strap, that is what they will think.  I am careful what I wear over it, though.  I am only three months on HRT, but already there's no way I can get away with wearing a T-shirt.

I have a band concert coming up next week for which the dress code is white shirt and black pants.  I am going to have to wear a bra underneath the shirt, so I had to go out and buy a white T-shirt to hide the bra.  My last article of men's clothing, and I am only going to wear it once.  By the time the next performance rolls around, I will be in girl mode and it won't matter what they see through my blouse! 

Before you get too paranoid about wearing a bra just keep in mind that lots of cis guys wear bras.  That is not something that will out you per se.   Have you ever checked out the male gynomastia forums?  It's more common that I had imagined.

I started wearing a bra when the girls got too large to hide anymore. I just went with it and tucked the twins under my t-shirt. No problem here.

Oh Kathy,
I bet you could find a white t-shirt or tank in the women's section that you could also wear later. Personally, I like it when my straps show just a bit.

Before I was full time and had some breast growth to hide, I used these sports bras if I remember rightly:

https://www.walmart.ca/en/ip/fruit-of-the-loom-built-up-sports-bra-white/1455223333562

They worked very well at hiding growth, and staying stealth under my shirt because of the smooth straps and under bust elastic. Eventually I had to layer two shirts to hide what I had, until I no longer could nor wanted to.

Those look a bit further from the neck area than mine.

This is the bra I wear.  I bought 2 "Skin" and 1 black and have been wearing them every day for about 1.5 years.

http://www.barenecessities.com/anita-rosa-faia-twin-seamless-comfort-wire-free-bra-5493_product.htm?pf_id=Anita5493

BTW, mine are 38A and have 2 hooks & 3 positions.

Use tape.