4. Fan or Shell
This popular pattern requires some precision and determination. Holding an Artex comb at a 25 - 30° angle, make a sweeping motion while pivoting on one end of the comb to create a half moon shape. Repeat in rows, from one end of the ceiling to the other. Create new rows below the one before, with the shapes placed half way between the two above it.
Using the same half moon shape, you can also create a shell pattern. Instead of a single sweeping motion, bob the comb up and down throughout the shape. This will create small, even mounds along the top of the shape, like a clam shell.