Sounds like you're getting close, but you should spend a little time solidifying the dream, and making it real for you before attempting to control too much. The moment you pop into lucidity, pause, and reflect. Reafirm to yourself that you are dreaming, and that you are in control. Look around you and take in the current surroundings. Feel your feet on the ground, concentrate on small details of the scenery you may notice. Many people like to rub their hands together, which seems to help focus as well.

For me, if all goes well, there is an instant where there is a little "pop," and suddenly everything goes from hazy to clear and my senses all turn on at once. If I can get to this point, I know I have a lot more control and experience a lot more realism as well.

I've found that summoning a particular person can be difficult, even after years of LDing. Often I summon the correct person, only to have them slowly turn into someone else. I think it's definitely harder than flying or teleporting, for example.