I gave a thankyou card and flowers to my professors for writing my LORs, but they were both women and I'm a girl and know them well. I don't think they were weirded out but enthusiastically thanked me. I just wanted to show my appreciation bc I knew they had a busy schedule and thought an email was too imperson.
I go to a small university and am close to all of my professors; so, I gave one thank you card when they completed my LOR along with a few brownies I baked for each of them (plus brownies and a thank you card for another professor who edited my personal statement). I also decided to give each a nice thank you card when I received my med school acceptance. It's nice to give a little something with the thank you card just to show how much you appreciate their time and help.