Developing ability

Hi there!
Well.. to cut things short. I am a seer, meaning I have visions from the past, present and future. Problem is.. I'm 18 now, and my ability still hasn't developed itself to it's full potential.
I've been told I'm at 20% now.
Does anyone here know of something that can help me develop it? Or is this something that just takes time and can't be rushed?
Thank you for your time,
~Mayenna