Colours: For instance, colours can be read with some knowledge and lots of practice. It takes just a few of colours, seven is often enough, and a basic set of meanings for each one. With practice, you will soon be using your rcolours as a focal point for your concentration, thus allowing your mind to focus on the information which is being channelled through to your consciousness.
Psychometry, sand reading and card reading, can all be achieved with a certain level of psychic development. You do not have to be mediumistic. Of course, if you want to communicate with the spirit world and give proof of life after death, then you must be a medium and developed to the highest level possible.
Some mediums are much more developed than others. The level of dedication needed is great. You need to spend so much time developing your psychic ability and then, if you are mediumsitic, your gift will start to show and prove itself with the evidence you give.
More on this subject in future posts.