I gifted large (Get Carried Away Tote, I think) Vera Bradley totes and matching wallets to my BMs. I received one as a BM once and I use it all the time, and the BMs have told me since how often they use it. Now would be a good time to buy with holiday sales going on!
I got my ladies small bags that can be used as a makeup bag or a small purse (from jujube called be quick) in the Harry Potter flying keys design. We're doing a nod to Harry Potter for our wedding and my bridesmaids all enjoy the series. I also made them earrings and bracelets and got them ivory shawl/scarf things since the wedding is in February and they might need a cover up. None are mandatory or even suggested to be worn for the wedding.
I refused to do robes. I had a man in my wedding party, so I decided to be as gender neutral as possible. I also wanted my gifts to be things they would actually use. The only personalized item was the tote bag with each of their first and last initials. It was simple and not overly feminine.
Towels from TJ Maxx or Marshalls(You can get them anywhere.)
Classic LokaiPrice online: $18Current sale price (12/2/19): $12.60I purchased 11 of these for about $2 each at my Jeweler's. I gave two of these to two guests who were bridal attendants because they helped us all get ready the morning of. One of them was my bridesman's girlfriend. My sister gave up her bracelet for this purpose, or I wouldn't have had enough. https://lokai.com/products/classic-bracelet Since my wedding day, I have seen evidence of my bridal party enjoying these gifts. My cousin took her tote, towel and mug to the pool a few days after the wedding and posted a photo on Facebook. My best friend dressed up and took her mug to Dragon Con in Atlanta. Her friend snapped a photo of her having her coffee and it seems to have matched her outfit.
I would say every girl or guy is different. Buy them gifts you know they'll use then price match to stay within budget. Example some girls in my group are girly so customized monogrammed compact mirrors and a cute tote. Make it special and personal.