Insert the stem through a piece of wire netting that is fixed over the top of a glass of water. You can use aluminum folio, the one used in the kitchen, and make a hole on it where you will insert the stem. Make sure that the stems are in the water. You can add a few small pieces of charcoal in the water to prevent the rotting of the stem. Also you can add few drops of liquid fertilizer to add the cutting to root faster.
Make sure you keep the water topped up so that the lower end of each cutting is always below the surface. In short time a network of roots will develop. Don’t keep the cuttings in full sun. When the cuttings are well rooted, plant carefully each plant into a 7 cm pot of sandy potting compost.
After well established, you can put the plant close to a window and in the summer keep it in full sun, this will help the Solenostemon to keep its bright colors. In the summer it also have some discrete light blue flowers.
Remember to keep turning the plants that are close to a window every week for an uniform growth. It might be necessary to renew the plant every year as it lose its bottom leaves and become less attractive.
There is a pinch pruning technique that is also known as finger-and-thumb pruning that can be apply to a Solenostemon. It consist in repeated pinch pruning as a plant develops to produce decorative shapes. All manner of forms are possible but the favorites are ball or pillar. Pinching must be repeated at frequent, regular intervals during the growing season, no tools are usually required.
Plants must be healthy to be able to respond to this technique. Always pinch prune young plants right from the start, encouraging them to form bushy mounds before beginning to form their own specific shapes.
With finger and thumb pinch out the tip of the shoot just above an opened leaf. Remove only the very tip to stimulate the maximum number of buds to produce side-shots. Side shots will then be break and develop into shoots. When those have develop two to four leaves repeat the process until you will have the shape that you want.