I think there are a lot of techniques that are quite similar, but also work well when used back to back. For example MILD is more about pre-sleep, so you will the be following it up with DILD. If you wake in the night and still feel like you are in REM sleep you can try a WILD as you go back to sleep. Or if you need the toilet in the middle of the night you can follow it up with WBTB. So although they are all seperate methods they all bounce off each other well, and can often use a selection all in one night