I read many other blogs. One of them by Becky@hemidemisemiquaverdesignblog.com,had a list of tips for guy cards. Briefly here they are:
1. Add texture
2.Keep lines clean and simple
3. Use metal,wood, chipboard,buttons, or fabric
I am trying to think outside the box for those special guys in my life and this entire article is great. check it out for yourself.