Mostly Paraphrased from my post in coven..
As this is just the basics on how to enter trance at will, thyself will be the whom.
You will need time, patience and in this case, music preferably instrumental, I suggest Moonlight Sonata 1st movement, my personal lullaby.
Somewhere free of distraction, where you can allow yourself to let go of the reality around you, your personal "haven"
With my personal belief magic is an inner force that all beings posses a way to manipulate that energy, a relaxed and subdued state, can do wonders for the craft as much as turning ones self into a bloody beast. Music is just a very beautiful art form and can assist the artistically endowed.
Give yourself as much time as you may need, in other words plenty of time, everyone is different persevere and remember to breathe!
The longest section on this tutorial, I will break it down in steps.
0. Make sure you understand that this may take some time, that you have the location, music or what ever you desire to make yourself feel at peace.
1. Start the music, ideally a lengthy instrumental on a loop if that is your fancy
2. Place yourself in a seated position or if you rather, lie down for comfort.
3. Begin the process of taking, a long heavy breath in through your nose, blowing out through your mouth
4. Take another breath, slower and deeper, this time hold it in count within your mind "one one thousand, two, two thousand, three three thousand" on the third count, slowly gently exhale through your mouth allowing your muscles to relax with this release.
5. Repeat this process informing yourself "every deep inhale, my muscles tighten, with each exhale they loosen, becoming lighter and lighter"
6. Ideally you will soon hear and feel your own heart beating within, the world around you will slow, and you will be much more aware of life around you..
This concludes the basics behind one of my many methods, I hope it was somehow helpful. since mental states are different for everyone Its a person to person basis.