I've been changing the checkout template and cart include template for a bit, also removing (or commenting out) bits and do whatever I want to do to change the styling here and there.
Is there some sort of checklist or task list somewhere so I can mock various states of the page to see how the styling looks? Right now I'm more or less editing field forms and clicking around to see what it does and then for example style a certain error/alert box or change font-sizes/colors whenever it pops up.
When I look at the templates there are more situations possible that probably need testing to see what I need to alter, but I'm not sure what's smart to basically go from A-Z? (if that makes sense).