I think it's important to always have around 3 sexual relationships at a time. I am not talking about talking to women or how many phone numbers. I mean 3 women you have sex with on a regular basis. This helps to divide your attention and energy. To reduce the likelihood of flakes, takes place during the Comfort phase of Mystery Method. Also I think it's more than just comfort. It's also rapport. If you have good rapport with a woman not only will she NOT flake, but if she does (usually it's out of her hands) she will be happy to make it up to you. Rapport is simply "a sympathetic relationship." Try to reach this level with her before trying to make concrete plans again since she has already flaked just to go to Walmart instead of having an awesome time with you. If you have already made plans for Friday then cancel Thursday. I'm sure you haven't done that with her yet and this will throw her off alittle. Then work on building rapport.