first coffee date, wear sandal or a heel?

I’ll wear a pretty b/w skirt with flower prints and a sexy (not revealing) top, this outfit goes well with heels, but should I wear a sandal to feel casual?

wearing summery print skirt with high heel boots is okay for fall ?

boots example :
http://z.about.com/d/shoes/1/5/J/l/high_heel_boots.jpg
skirts examples :
http://www.successfullydressed.com.au/catalog/images/Animal%20Print%20Skirt%20-%2046.jpg
http://www.angiehearts.net/v/vspfiles/photos/jk5100b-2T.jpg
sorry for my english, i am not native speaker. i think i meant “flower print” skirt or something like that