One thing which may help in this situation is to fix a set of rules in your mind. One of these rules should be: 'I am only submissive to someone I choose to submit to' because that is how it works - you choose to submit to someone who deserves your submission. Other rules will refine this - give you the freedom to choose to do things because you want to, because it needs to be done and so on. Through all of this should be the techniques Jennifer mentions about saying no and realising that that saying no to someone does not make you a bad sub (saying yes all the time to someone who is not your official Dom/me may make you a bad sub).

Formulate these rules yourself, write them down, memorise them and bring them to mind whenever someone asks you to do something. Always bear in mind the mantra 'you are not my Dom, why should I do anything for you?'. In situations where this happens, always be aware that you can negotiate - 'ok, I'll get that from the car for you, but you are washing the dishes tomorrow'.