Numbness and tingling in your feet can be caused from tightly fitting shoes that cause what is known as a compression neuropathy (pressing on a nerve). If you are wearing a pair of running or exercise shoes, and all of a sudden you get a tingling sensation or numbness feeling on the top of your foot.....you are probably tying your shoes to tightly. It can also occur if you are wearing a tightly fitted dress shoe and stand for a long period of time like a trade show. A reason that this type of problem can occur in your feet is because there are superficial nerves that travel on the top of your feet that can get injured or irritated when micro - traumatised. It can send sharp pains into your toes or just cause your toes to tingle or get numb.
To prevent this problem from happening make sure you loosen you laced shoes when you feel the the slightest sensation of pressure on the top of your foot. Also make sure you wear comfortable shoes with an arch support in them when you are at trade shows. If you are wearing high heels there are arch products available that can fit in your shoe to give your feet support. Icing can also help if you begin to experience the tingling sensations. If the problem continues to persist consult with your foot specialst.