theres pansies/violas, primulas, double daisiesetc. my local garden centre had quite a lot of autumn plants in flower, you have to be careful that what you buy is frost hardy but if its soon you could keep plants in pots frost free for instant effect on the day

Pick up a couple of Skimmias, some pansies, variegated ivies and make up a couple of pots either side of the front door. Can't recommend plants for the actual garden, don't know how big or small it is, which way it faces, what's in it already, etc.

Ornamental cabbage and kale, too.

Think I would just put loads of pansies in, they are lovely at the moment and you can get such an assortment of colour, pack them in and they will look a treat.