dont sit on your couch! get a ball and always sit on that! try not to slouch! hands and knees is great for getting bubs in to position i recommend scrubbing your floors with a small scrubbing brush the stretching and wobbling all helps.

and research breech birthing because some times they just dont want to turn!
although this being your 3rd baby every thing is very stretched and bubs has plenty of room to do its somersults and half pikes!hehe