How do you create gear on zwinky

You can't - The Zwinky people do. You CAN send in a idea by going under Feedback, or if it's clothes go to your Wardrobe, go to the last piece in say, shirts and next to it is a hanger with a little sign. If the link on there won't work, go to:
http://feedback.zwinky.com/index_nontech.jsp?key=zwsugg
=D