I have never been particularly adventurous with underwear. I generally wear black or nude bikini briefs and Primadonna bras in dark or neutral shades. I sometimes wear Spanx if I need a smooth line under clothes but otherwise as long as they are easy to wash and comfortable to wear, I tend to wear the same style and brand all the time. My husband is pretty much the same. He subscribes to socks and underpants online and gets a back every couple of months. Same style, different patterns.
One of the best things I have ever done was to be professionally fitted for a bra. Like most women, I tended to wear a too-big back size and too-small cup size. Wearing bras that actually fit me made a huge difference to the problems I had been having with back and shoulder pain, my bras riding up, and not having a clean line under clothes. I am a 32/75 back size and H cup size so I really need cantilevering to be comfy. But even if you don’t, have yourself professionally fitted if you can.
But for people that are more adventurous than I am, this site has a great breakdown of styles, problems and advice.
For bras, r/abrathatfits subreddit https://reddit.com/r/ABraThatFits/s/jwgkLsJ2Iv
or website (calculator – https://www.abrathatfits.org/calculator.php ) are the absolute best places to find out one’s bra sise/best shape. Not all bra shapes/styles work for all breast shapes. The underwear images are fine, but the bra ones are reductive & only useful really for a very small segment of bras available (and many shown won’t be at all useful for the majority of breast-havers).
The Irish Bra Lady on IG (https://instagram.com/theirishbralady?igshid=NzZhOTFlYzFmZQ== ) posts debunking photos (what people think a size looks like, and what it actually is) & shows before & afters.
As someone who was forced to wear matronly swimsuits & longline orthopaedic-style bras from middle school, there is a lot of misinformation about bras & bra sizing out there.
Thank you!