Colour on colour
I love to play around with colour combinations, and - especially recently - I have been making a lot of beads out of opaque glass decorated with stringerwork in transparent glass.
The depth created by layering a coloured window over an opaque base colour is fabulous - for instance, transparent dots that are melted smooth over an opaque base resemble deep 'pools' of colour - but there is the additional appeal of a new colour being created! Transparent green over blue creates a lovely kingfisher colour, and green over green becomes, well, even greener. Much fun can be had by putting glass on glass.
It doesn't always work, though. I've recently taken delivery of a new shade of transparent purple which I thought I'd team with some opaque turquoise. I have several reactive purples which look just glorious layered over opaque turquoise - but this non-reactive one just didn't 'pop'. It's created a much duller effect akin to what would be produced if I mixed turquoise watercolour paint with purple watercolour paint - it's a sort of muddy purplish elephant grey. Not hideous, but at the same time not altogether desirable.
Compare the purple-on-turquoise, though, with the teal-on-turquoise. Now that's just a gorgeous combination!
Transparents can give other transparents an extra touch of va-va-voom, too! The beads below are transparent green - the plain one is just one shade of pale emerald, and dotted one has a core of bright acid green which has been encased in the same pale emerald. Now that is GREEN in a much bigger way!