To develop your clairvoyance, you must be able to attain a higher level of consciousness. You need to work on your spirituality and this can be done in several ways. The most common way is through tapping the power of your third eye. Another effective way is through constant meditation.
A brain must have space. So what is space? Not only the space between here and there - space indicates 'without a centre'. If you have a centre, and you move away from the centre to the periphery, however long, wide the periphery is, it is still limited. This is Sixth Public Talk of J Krishnamurti in Madras, Talks from the series This Light in Oneself.