For the plants that had finished their flowering period, like Winter jasmine or Erica carnea, is time for you to prune them now for maintaining them in shape and encourage new growth. For early flowering bulbous plants, like snowdrops, is time for lifting and dividing them while still in leaf just after flowering, or plant new ones as they will established much better now than planting dry bulbs.
Clematis will have a special pruning treatment in this period as many varieties can be pruned hard back to buds at the base of the main stem for a new and healthier start in the spring. Old dead stems can be removed completely in this period, but do not forget to feed them after this hard pruning.
Keep ordering summer and autumn flowering bulbs, corms and tubers, order seedlings and young bedding plants and all the other seeds that will be plant directly outside when spring will come.
For your kitchen garden now is the best time to stat planing it and start sowing early vegetables in a cold frame for planting them outside later or under cloches. You can sow them in pots also and when the time will allow, you can just move them into the garden.