Etoile, there are other threads that discuss the emptiness and quieting the mind. It might be helpfull to use the search feature and read some of these.
I would like to add that going into the emptiness has different layers (depths). When Master Lin says to think of nothing it is to help you go into the emptiness and "connect with the universal energy". Then, not while, you use your conscious mind to direct qi. Connecting with the universal energy before directing qi amplifies your ability to work with the qi; as does calling on your master's energy.
I just wanted to add that information, since I perceived some confusion.
Also have a relaxed, positive attitude about how your meditations are going. Be Kind to yourself, Forgive yourself for not being perfect, Love yourself and the experience exactly as it is. It IS exactly what it needs to be. You should not judge or label the experience, just do the meditations and be in the experience. They will progress without your trying, just simply by doing.
If you would like, you could review Master Lin's six keys to success and see if any give you direction.
You are perfection.
Iam2 