Practice Before You Get Your Drill!
WHAT YOU CAN DO NOW - Practice writing on glass with the sharpie! Wipe off anything you don't like and keep what you are happy with to engrave later! Print designs or letters you can use on the flat glass and trace them. Something like the search below - https://www.google.com/search?q=simple+clip+art+black+and+white&tbm=isch&ved=2ahUKEwiJ3-T78IfvAhVMs1kKHTDEACgQ2-cCegQIABAA&oq=simple+clip+art&gs_lcp=CgNpbWcQARgCMgIIADICCAAyAggAMgIIADICCAAyAggAMgIIADICCAAyAggAMgIIADoECAAQQzoFCAAQsQM6BwgAELEDEEM6BggAEAgQHlC6e1icwwFg7NQBaANwAHgBgAGUAogBkhKSAQU5LjUuNJgBAKABAaoBC2d3cy13aXotaW1nwAEB&sclient=img&ei=-BU5YImDB8zm5gKwiIPAAg&bih=754&biw=1536 Get a feel for how to write on the curved surface. - ~Make guide lines on your bottles or project to keep your writing in a straight line ~Use upper and lower guidelines to help practice keeping all your letters the same size ~Work on centering! You need to plan where your words will begin and end on the surface so that things are centered. Especially important when you start doing wine bottles. ~Don't forget you can do more than letters/words. Draw a picture if you want! I did attach a sheet to give you an idea of what may work for the Mother's Day bottles.