Thanks! That is really helpful, practical advice. I definitely get tripped up by the stopping thing; it's like this weird politeness reflex or something. Your point about 'training' others to talk over me is quite insightful.

Although it probably doesn't come across this way from my previous post, I'm actually pretty relaxed if someone innocently/accidentally interrupts me. I'll usually do the whole 'no please, after you' thing. But I can see how I might be creating a rod for my own back if I do this in the wrong situation...

So thanks again for the advice: I need to stop conditioning others to interrupt me. I'm assuming I'm not allowed to go in the complete opposite direction with this though: immediately applying aversive stimuli when it happens. It might be a little unprofessional :)