Glass paint and supplies.
Glass painting is easier than you think. Create your design on a computer and print it out. Then place this behind the glass to be painted and just trace it.
Types of glass paint include simple waterbased such as Anitas Aquaglass. This is simple to use but is only designed for decorative items. Pebeo Vitrail is a spirit based glass paint, agin only for decorative items but the colours are much more vibrant than the Aqua Glass paint. Lastly there is Pebeo Vitrea 160. This is a heat set glass paint that is fixed in a domestic oven (perfectly safe). Items painted with Vitrea 160 can be washed in a dishwasher making it ideal for items such as drinking glasses.Aquaglass - Waterbased suitable for decorative purposes