A lot of people put mustard in but I don't like the flavor personally. If you like the flavor of mustard in it then you are in luck because if you add mustard to the egg yolk at the beginning, it helps build a better emulsification and the mayo is more likely to turn out good rather than separating.Those are great tips naturally. My wife makes her own mayo too and I think it really makes all the difference. It is very time consuming so be prepared to take your time over it. We put mustard in for flavor as well as the salt.