Mixing masonry mortar properly involves using a proper ratio of the mortar materials, using sand of a good grade, and storing the sand and cement properly before using them. Preparing the mortar at the right time to use it within 90 minutes after mixing, and mixing the mortar to the correct viscosity are also important tips. One way to determine if the mortar has proper viscosity is to create ridges in the mortar and see they stay intact without collapsing.
A proper cement to sand ratio is 1 to 3 for a wall that is free from weather elements such as rainfall and wind. For a wall that is likely to be in contact with the elements, the mortar should contain lime to enhance its strength, and the ratio of cement to sand to lime should be 1 to 4 to 1/2. Using a good grade sand to mix the mortar helps to prevent cracks resulting from expansion and relaxation of the mortar during drying. A good grade sand does not contain clay.
Proper storage of sand and cement involves protecting them from moisture absorption by covering the sand and keeping the cement bags closed in a dry place until the time of mixing the mortar. This ensures that the correct amount of water required to mix the mortar remains intact.