How do I start rose bush cuttings?

Answer 1

Simple.

Get a new branch that has already flowered with at least 4 branches or 6 nodes.
Remove the lower two.
Dip in water immediately and then root stimulator.
Place in good potting mix and water well.
Keep watering.

If you watch a nursery, a lot of times they will grow roses this way as well.

A more in depth description can be found from the following website.

Answer 2

To start rose bush cuttings, you cut below where a stem joins a branch forming a V. You cut below that.