I use it to separate ideas and phrases which I'm sure are important. This is to draw attention to each phrases contribution to the overall effect.
I also use the white spaces to represent silence. How can you say so much with saying little? That is the idea.
If you look closely you will notice that there are no punctuations in the poems. Punctuations are replaced with those white spaces..
You should look to some modern writers American (latin and African), European and African. You'd be surprised at experimental styles of poetry that are out there.
RE: White spaces: experimenting with silence.