In late summer after flowering take a shoots that are still green.Make the cut just above a leaf node at the junction of the green and woody part of the stem. Remove the lower leaves to cut down on water loss and cut off the soft tip. Put into a deepish pot of sandy compost. If you have a propagator use it, otherwise put a plastic bag over it and keep over winter in a cool frost free place.
For seeds wait until the hips are ripe before removing from the plant. Roses from seeds will likely not be like the parent.