I'm in love with these jewel nail decals by Jolly Good Studio. I'm big on supporting other crafters, so when I saw these (and obviously fell in love with them) I couldn't resist.
I only used three on each hand (I want to make them last!). They are very easy to apply. Just cut out a gem, apply a little water with a paintbrush, slide the gem off the backing paper and apply to the nail. A good top coat will seal it. I applied the decals over Topshop Tidal which is such a pretty grey-blue colour. I love it.