When chrysanthemums have stopped flowering you should cut them back and dispose of the resulting waste.
You should cut back perennials that have died down this month.
Herbaceous perennials that have faded can now be cut back: simply add them to the compost heap!
Remove spent flowers of euphorbias: cut the flowered stem back to ground level! About euphorbias: http://j.mp/K9qObl
Let spring-flowering bulbs die down before cutting them back! What to do with fading bulbs: http://j.mp/J7blsA
Hardy evergreens can already be pruned if necessary! Some gardeners cut them in quite unusual ways: http://j.mp/zINWIr
Shrubs such as Cornus are usually cut back very hard now! Cut branches put in a vase may even root: http://j.mp/zIvTns
Autumn-fruiting raspberries can now be pruned: cut back the canes to ground level! On pruning raspberries: http://bit.ly/wc1f0g
Do you have to control ivy? Cut the stems back to the ground and dig the roots out! On green ivy: http://bit.ly/wdQpMY