Meditation tricks
All skills need to be learned and the best way is to... practice, practice, practice!
Relax those facial muscles
Everyone starting to meditate learns that the first step is about relaxing your body. If you're not accustomed to this, start with relaxing your feet and state this either out loud (preferred), in your mind (as you become more advanced) or just will it (advanced). You know you can advance in these stages when there is no "argumenting" anymore in your mind or doubt. You just know and feel it is whatever it is :)
Proceed higher up your body to the top of your head as your progress from the mind into the beyond, which is the most crucial step towards a light and deep trance state.
As your body is relaxed and you tune into yourself, you either see blackness or some images. You must learn at any moment to become aware of your focus and how this focus contracts your facial muscles. When the muscles are not relaxed, you resist getting into this deeper relaxed state. I find this harder to do when I have visions compared to looking in the void.
Pause if needed during your meditation and relax the muscles in your face by contracting them and pinching your face for a few seconds before relaxing them again. Repeat this as often as needed.
With a relaxed face, your mind relaxes much easier.
Calm a busy mind
When you have a busy mind and easily follow the thought train, just open your eyes where you are. Look at all the objects in the room and become aware of the air or space between them. The air and objects are all energy, the latter just a denser form of it.
Now close your eyes and try to take a step back in your visualization/imagination as if you are sitting in a movie theater. Observe how your thoughts are like objects floating around (either through visions or a sense of knowing).
Now concentrate on the space between the objects, the emptiness and try to feel how this differs (I sense more peace). Gaze deeper into that space and focus your attention into it without forcing (facial contractions?)
Take a step back if needed to visualize the objects floating in space. Now focus again on the empty space and just let it everything else go.
At this point I tend to float in space, getting an impression of stars and planets far away and all is quiet and peaceful. This state is a deep trance state when you experience the sense of not present in the body anymore.
I don't see any images or shapes so I don't know if I can manifest
This does NOT mean you can't visualize or manifest. On the contrary, you have an advantage because you can feel better if your manifestion is truly something that is for your Highest Good (see below for my opinion about this).
Write down what you want and take your time to already feel into it. Especially focus on characteristics of the manifest (e.g., for a job: nice co-workers, honest pay, honest time off...)
Once you think you have your manifest ready, go into meditation as deep as you can.
Rather than trying to see something, just imagine it is there. Know it is there. Believe it is there. With that belief of your manifest being in your focus, call in the vibration of the qualities you want it to be. This is what brings the manifest to life, equally when you can clearly visualize. Without adding vibration and some specifics of your desire, it's just an empty vision so you need to call upon the Universal Language.
Once that is done, focus on yourself. Let those feelings of joy, gratitude, love, faith and belief rise up so strong and powerfully until you feel like you will burst if more arises.
Channel all of this energy inside you towards your manifest that is a little outside of you where your focus was. Know that your energy envelops the manifest.
I personally copy this energy ball into 3 identical ones. First I send one to the center of the Divine Source, the second one to the Divine Mother Earth and the last one I absorb into my solar plexus chakra and sense where the energy flows. Any areas that my attention gets drawn too, I assume thats is where there is resistance/blockage and I focus my intent to allow the natural flow to occur in the area.
Once you feel all is up and running, remain in this state as long as you like.