I went for really basic ones - layer of compost, layer of miniature daff bulbs, bit more compost then lilac violas in the top. When the cheapo multicoloured primulas appear in the DIY stores, they are usually very small plugs, so a few of those can be popped into the basket top later on for extra colour, without damaging any of the daffs if they've started to grow. Dead easy.
If you don't want bulbs popping up then a bit of ivy, maybe an evergreen herb or two so it's dual purpose, and lots of pansies/violas at this time of year. Winter ones are so much easier!
moonbells