Does anyone have any tips for getting rid of mental projections when APing via a lucid dream? I tried saying 'erase illusions!' and spinning but neither of them worked.
First, you are already projecting via a lucid dream. There is very little fundamental difference between a lucid dream and an astral projection. :)
Secondly, the reason you're getting... what you're referring to as "illusions"... is because your mind isn't focused. Your chaotic mind is fueling most of what you experience around you in a projection. To stop the illusions you'll need to get your mind under control.
Learn to meditate.
Learn to focus your mind towards something.
Then learn to hold that focus for extended periods of time.
Eventually as you practice this, it will naturally come across in your projections... and your physical life will also vastly improve in ways you didn't even realize possible. :)
Good answer! :-)
For this, You have to do more and more practice and you have to learn what Xanth said.