Many factors change between day and night and we can use this to our benefit. For example do the simple walking drill when you walk into a partner and they have to evade but with the thought to keep the sun at your back so he will have a problem to see you and learn to work through this difficulty. Another way is to wear sunglasses and than turn on bright lights in a dark room and work your way out of there. The principle is clean and your use of it can vary according to the situation. Use your head and in the logical way for it.