I promised a poster a list of stuff to do while lucid or OBE- hadn't completely forgotten, so here it is.

Things to do while projecting-
In the RTZ, practice flying, floating, and sensing. Try to sense when you don't see.
Observe around you, and identify anomalies.
If anomalies are doors or windows, go through them.
Do energy work while in the RTZ. Try to produce light balls in your hands.
Find your own body, mess with it. Try to do energy work on your body. If it gets weird, you may turn it into a mental-in the RTZ projection. Enjoy! (and no, I don't mean sex. That would be too weird for me.)
Go through walls. Feel the texture, feel the sense of semisolidity and sometimes even taste of the material as you go though it. Don't be surprised if you find yourself in the astral on the other side.

In dreams, attempt to reach lucidity. Keep a journal, use keywords, use lucidity techniques and affirmations.

When lucid or astral projecting-
Experiment with travel. Fly, float, teleport. See which one you like the most.
Go through things.
Observe objects, people. Consider that they are alive (including trees, rocks, objects).
Attempt to communicate with objects as well as beings.
Ask characters who they are. If they don't respond ask them if they are parts of you.
Ask them what they are supposed to represent.
Attempt to communicate using thought.
If you're brave attempt to communicate by merging with the being/object.

Look for vortexes, go into them.
If you're in an astral landscape and have done all the communicating you want, wave your hand in front of it, as if to erase it. See what happens.
If the environment dissolves, see what's behind it.

Attempt to find (you can use affirmations before practicing) teaching temples, attend dreamstate lessons.
Try to finish the lessons or figure out what they mean.
Practice TK (controlling the environment), bringing things to you (manifestation) and continue to communicate with entities that you feel comfortable with.

Practice meditating and using astral sight in the astral, such as 'seeing with closed eyes' while in the astral. It's interesting.

If more ideas, please contribute.