The suggestions posted here, are excellent suggestions.
The examples Lorelyen gave for changes in perception are particularly interesting.
What John said about being open minded hits home as well.
Other methods I have tried are practicing visualization. The best way I personally know how to do that is by reading for others, and practicing intuition in conjunction with opening the third eye. When I began practicing with others- what I have noticed over time, is not only has intuition been strengthened but also that imagery in the mind's eye is becoming accurate as well. It takes time and practice, and can at times seem slow going, but if you are diligent and have fun with it, you will begin to notice your own ability improving, and yourself gaining in confidence. So remember too, to relax and have fun trying it.
My first work with my own third eye area involved meditation on the area on the forehead between the eyes- middle of forehead, with an amethyst stone. The vision that transpired from that was incredibly powerful, almost over-powering. Not an entirely bad experience itself, but produced euphoria and tingling on the forehead area as after effects- that were quite strong. But you do not have to do anything like that yourself. Personally I would suggest listening to the suggestions by the others here in this thread, they're great suggestions.