What is the best way to disguise yourself?

That could depend upon your reasons for wanting to disguise yourself. You could certainly make yourself unrecognizable by disguising yourself as an orthodox Muslim woman, and wearing a burkha, which conceals all parts of you except for your eyes (and you could also wear sunglasses). However, that might make you conspicuous, even though unrecognizable. Hairstyles are the easiest thing to change, and can change your appearance quite effectively. Growing a beard (if you are the kind of person who can grow a beard) creates a very big change in your appearance.