Hi,
Summoning a friend can be attained easily by calling his/her name aloud/ turning back expecting/open a door to see him outside.
The second thing, as getting back to your bed room is quiet risky as your physical body is lying there. It is more likely to return your awareness to your real body and lose lucidity.
So, to stabilize your dream, you have to forget your physical body by touching everything in your dream world, and,
there are plenty of bedrooms other than YOURS in this universe!!!!!