Pinching soft growing tips
A small pinch can encourage some plants to branch.

What to look for
Look for a soft, actively growing tip and the nearest healthy leaf node. This is suitable for some branching herbaceous plants, but not for every plant or its only growing point.
What to do
Pinch or snip a small amount just above the node, leaving the node and surrounding leaves intact. Start with one stem and watch the response; skip it if the growth point is unclear or the plant is stressed.