I sometimes get 'analysis paralysis'. Maybe I should use this fabric instead of that. Maybe a pieced sashing. Maybe draft a PP version of the block. I obsess and never seem to start. What I've found is if I just start cutting one of the fabrics (usually my least favorite) , then everything starts rolling along. For some reason it breaks the log jam for me.
Just grab a fabric & start cutting. Maybe the one with the fewest number of pieces?