You can try youtube videos on the subject. They give great tips.
One thing I as a newbie can teach you. I have the same problem. Only when I fall a sleep the first time or the second time then I automatically seem to get the TGS. I can hear voices and see things. So now the task to control this.
This means that you need to take the correct amount of time to get in the TGS (theta-gamma sync) or power meditative state. Someone adviced. Don’t find it strange that you need at least 20 minutes in the beginnen.
Another thing the above tells you, being tired helps. So do it before sleep or after a busy working day, sports etc…
Reading and learning about it puts your subconscious in the right state to. For example reading about the spirit you want to contact.
The most important thing is, take time and don’t give up. And yes that’s hard for me to.