Tips/exercises for finding your voice

Hey guys,

I often find that the hardest part of writing songs for me is finding the angle or the voice from which the song comes - even the subject matter. Once I get that first line down, it tends to flow a lot easier.

But I have issues starting 99% of the time, which makes me feel that I'm wasting opportunities (that impulse that makes you grab your instrument) - and I really do want to improve upon this in any way that I can.

Does anyone have any exercises/tips that can help me find a rhythm with songwriting or a greater ease with getting words on paper? Anything at all really that you have used or heard of people using to get the wheels turning.

I know it's a very loosely written question - so any insight would be appreciated.

Thank you.