Astral projection is only as dangerous as you make it out to be. That’s the nature of things like this. It is a very personal, subjective experience. If you believe you encounter demons while projecting, then you will. Your thoughts and beliefs will attract to you the things you believe in, especially when you get into more spiritual things like astral projection.
If you believe you are safe, then you are safe. Maintain this belief and you’ll be fine.
That aside, there really is no substitute for disciplined concentration and focus. You can use drugs, certain hallucinogens or the like, to bring about the experience. But that may be detrimental in the long run if you’re not careful. However, I did think of one thing.
There are different ways to help concentrate. Meditative methods can be considered an inhibitory practice of slowing yourself down to initiate the trance to project. But there may be another way, more conducive to your self.
The other methods I have found are what could be called excitationary, meaning you “excite” yourself into a trance. Some shamans did this in the past by dancing and drumming (oftentimes aided by drugs, but they are not absolutely necessary). In particular, a form of Chinese shamanic tiger qigong uses dancing and certain qigong movements which may help you. Research “Laohu Gong” for more information.
You may have better results with excitation than inhibitory. The two keys either way are time and patience. You won’t achieve it all in one day, but you will achieve it if you are determined enough and put in enough effort for enough time.
Best of luck on your search.