How does one prepare to write from the past, present and future?

I approach this from staying in a contemplative state as much as life allows me to. When I can do this it allows me into a "HEALING" frame of mind in healing myself and others on all levels. From this healing frame of mind often I know one day what I need to write about and then I do. Writing for me is like having a conversation with myself in some ways. Writing in some ways is like playing God maybe where you can see the relationships and then you just have to describe what happened in the past, present and future like it was when you were actually there.

It's similar to writing about your childhood if you are 50 to 100 or more years old. You remember how it was then and the people in your life except that most of them are dead because you are much younger than the people you knew as a child mostly unless you were in school with them. So, you describe all this knowing the people reading this may or may not get what you are actually writing about because they likely were not there unless they were your exact age living in your exact town or going to your exact school.

My experience of all this is if you imagine a diamond of hundreds of facets which is your soul. 

Then you imagine that God is like our physical sun. Now imagine that physical sun's light bouncing off the diamond (which is your soul) and each facet of light is another incarnation of yours in the past, present or future. So, from your soul's point of view you have already lived all your lifetimes in the past, present and future already right now.

This is the reality of what a soul actually is beyond time and space. 

NOTE: when you are trying to describe something (a soul) which does not naturally live in time and space at all unless it is clothed with a body in a place like on Earth you have to get into metaphores  to more accurately describe what you are talking about.