I've considered myself a reasonably competent backward skater for years now but have recently realised I am still leaning a tiny bit forward when skating backwards.
It's especially noticeable when doing alternating crossovers/backward runs which is my go-to element for continuous backward skating. I creep forward a bit for the run part. It's also noticeable when doing back cross rolls on rollerblades, which are poor compared to those I do on ice. I wear a helmet on rollerblades to boost confidence but still resist - the tail on them is much shorter than on my figure blades so there is the worry that they will disappear from under me.
So I have been working on really standing tall and straight with my upper body, when going backwards. And leaning back on my cross rolls more. With some limited success.
Also managing to open my hip more on upright spins, which makes it go faster, be better centered and stay over my spinning foot.