balance all your chakra's, don't focus on just one because it will unbalance them and you will get negative results. a third eye that's too open causes really bad headaches among other things. it deals with insight, creativity, and yes psychic skills.
you open it normally through meditation as you would all of them. start from your root chakra and work your way up to the crown. the third eye is the 6th so you'll be a while. i typically tell people to balance one a day for a week so they can focus on each one. record the day before and then the day of to track any changes you might notice with the balanced chakra. if you have trouble balancing a third eye chakra, an amethyst crystal over your chakra can help open it easier.
that link should help you.