Buying for someone who is into pilates is harder than it looks. Equipment is expensive and personal, clothing means guessing a size, and anything with a brand logo is a coin flip on whether they like that brand.
Why socks work as a gift
They are one size fits most, so you are not guessing. They get used every single class rather than sitting in a drawer. And most people who take pilates regularly own two or three pairs and are quietly annoyed about it, because one pair is always in the wash.
What to look for
Grip that covers toe, edge and heel. The whole point of the gift is that it works in class.
A crew cuff. Stays up, and looks intentional with leggings.
More than one pair. A single pair reads like a stocking filler. Three or more reads like a gift.
What to skip
Grippy socks from a general sportswear rack with a few dots printed on the sole. They are usually thin, the print goes smooth in a month, and your friend will know.
Our gift boxes
We put three, four or five pairs in a pink box with tissue, a cotton drawstring pouch for carrying socks to class, and a welcome card. The styles in each box are fixed and listed on the page, so you can see exactly what you are sending.

The card has a To and From line on the front, so the part that makes it personal is in your handwriting rather than ours. The back is a hand drawn sock illustration.