I found that for its success it is essential to have a "penetrating" mind and therefore a capacity for concentration rather high, definitely a not common peculiarity.
Training your mind to concentrate it's not an obvious skill, and one has to train it.
Initial practice can be frustrating, but over time you will be very satisfied with yourself; entering trance will no longer be a problem.
I advise you to focus on the state of concentration and relaxation of the mind, through meditation on the void, pranayama, and meditations aimed at developing visualization concentration, such as those of purification, protection, and the "foundation" one.
When I first started taking meditation seriously, I even found that with intense practice of the meditations listed above, a light trance state is naturally induced. Furthermore, not having a prepared and strong mind, trying to enter trance I systematically fell asleep.