I'm getting on pretty well with the labials as you all them but I can see my tongue wiggling about behind my teeth.Do we have to live with this one, because I can't see how we can get round it. I tend to reposition my mouth slightly to offset it.Is it that important none of us are going to get closeups.

You can try making the sounds further back:
What you are doing is trying to match the m sound that you would normally make. Try making the ng in different locations of your mouth. After each time make your normal Mmmmm sound and see which comes the closest. By different locations I mean trying to arch the tongue at the back of the throat as you normally would for ng (as in sing, ring, thing). Then try arching the tongue midway between the teeth and the back of the throat to shut the air off there instead. Does that sound better? You can also shut it off by putting the tip of your tongue at the top of your front teeth (in the back, silly). That is a lazy n and is easiest, but not always the best.

For p, try a kuh sound and for b try a guh sound. Those show the tongue less if you are doing tv work.

Tony as always, you come across with those great ideas. Another good idea is to invest in the Maher course they have many great ideas in how to position your tongue to form words, don't get discouraged, I am a newbie as well and still having trouble with the labials, hopefully I will get some one on one pointers when i get to the VHC in July.
N J