use a special roller with the texture you want, i recommend to use Plaster of Paris designs to texture the ceiling
POP false ceiling design POP roof design
I Would Like To Know The Best Way To Texture My Ceiling
Use a 1 in. Nap roller pad thin material by 1/3. Roll evenly for the desired effect [thick or thin] this can be knocked down, flattened by a large trowel, to achieve a tree bark appearance. Wait till its almost set up before trowelling