Folk tradition says that abundantly fruitful autumns are followed by hard winters, so that's a good excuse to take cuttings of everything around you, even though it may not be the "correct" season for some things. A higher strike rate will be achieved if a few basic rules are adhered to. The most important thing (or so says expert propagator Assumpta Broomfield of Irish County Garden Plants in Portlaoise) is to make sure that the cuttings don't have a second to dry out after you remove them from the parent plant.
Use clean equipment (knives, compost, pots, trays etc.). Choose healthy parts of healthy plants for cuttings. Pop them into a plastic bag immediately and don't handle them unduly. Prepare cuttings one at a time, leaving the others in the bag. Remove excess leaves, trim beneath a leaf joint and firm into a pot or tray of cuttings compost (one part sand and one part peat, or peat substitute). Water and cover with a transparent plastic bag to maintain moisture. Stand in a bright (not scorching), warmish place. Check for mildewy or rotting leaves once or twice a week.