And, if you're not sure if you're doing it right, I bet it would be pretty easy to find some visually impaired folks who would be incredibly happy to give you a lot of very detailed, specific feedback.
Absolutely! Many of our very best and most involved beta testers are visually impaired; their involvement and feedback's been invaluable -- not just on matters of accessibility but also/especially when piloting new & experimental features -- we've been extraordinarily lucky to have their support and assistance.