I think I get the vibe you're going for. I have a selection of colorful oversized shirts and t-shirts that I think do a decent job (a lot of tie dye). That kind of fit helps to obscure my body type a bit since most tops fit me very tight in the shoulders and chest. Other than that I sometimes paint my nails random colours and generally keep my hair on the longer side. More than anything else I think the neon green nails make it hard for people to just assume "man", and it doesn't necessarily have to look super girly either.