Anything that makes you look like a capable and intelligent woman.
Men hate that.
In all seriousness, I have found that wearing a shirt with a collar is fine, but when combined with boots and a car with 4 wheel drive, I might as well be an anomaly that must be studied with limited interaction so as not to disturb the delicate balance of both feminine and masculine characteristics. As we all know this is a naturally unstable and volatile mixture that can explode resulting in a wide array of terrifying creations.
Yes, I go hiking, fishing, and lift heavy things. Yes, I like my pants to have functional pockets. Yes, if I were a man my dick would definitely be bigger than yours. Seems like the obvious conclusion. No reason to feel threatened.