if you're self-taught, you don't want to hear from us.
then you'll be us-taught.
it seems as thought your work is tiny.
or you have a very large chair on which to photograph it.
i prefer to work larger.
more room for the physical aspect self epxression.
but i've also been told that this "size obsession is a man thing"
so take that for what it's worth.
i'd say try a bunch of different sizes to see what you like.
just keep doing what feels right.