Wearing two different shoes at the same time.
Wearing one shoe of a different brand/style/color on one foot and one of a completely different brand/style/color on the other foot.
Wearing two shoes that do not match
Today I wore my Reebok Pump with my red Air Force One.
"Hey Bob. I see your schwerpin today."
"Of course Jim. I schwerp all day. It's all I do."
"I sure do love wearing two different types of shoe Bob."
"It's the coolest thing in fashion since fur!"