I don't even own any crew neck (high neck) tees anymore. All are either scoop or v-necks. Easy to find in most any store. Most of my clothes these days are what is considered technical. Meaning designed for fitness activities like running, hiking, biking, whatever. They come in many colors and cute styles. Anyway, technical fabric is very thin so it layers well. And they are cute enough to wear for everyday as well. Also can pack without wrinkling. Yay! I would think you could easily find scoop or v-neck short sleeve tops that would work under your sleeveless tops without adding any bulk or ruining the neckline if you look in departments that sell these types of clothes. Or try a sporting goods-type of store. If you have one, REI has a fantastic selection. You can also order online. Like Nordstrom is famous for, they have a "no questions asked" return policy. However, you may have to pay for the shipping?