How do I paint glass?

I have tons of little votives that I’d like to paint and give out to friends and family…each one being personalized in some way. I know I need to use glass paint, but what is the best brand? And what is a glass conditioner? Do I really need it? Also, for the finishing spray…is there any specified type or can I just use the same spray I use on my acrylic paintings (on canvas)? Thanks in advance.