A foundation mix of one part cement, three parts sand, and six parts aggregates can be employed. Half of the cement, sand, and aggregates (for a concrete mix alone) should be measured. Using half of the mixture now will keep it from drying out before you get a chance to use the rest. You may combine the remaining half afterwards. If using cement, add it while stirring. Mortar is the same as concrete with the addition of water. The correct amount of water depends on how thick you want your finished product to be. Too much water makes for soggy mortar, which is no good for building anything. Too little water leaves the mortar too hard, which isn't very useful either. You can test your mortar by squeezing a small amount between your fingers. It should be able to stick but not tear away from whatever it is being attached to. If it doesn't feel stiff enough, add more water. If it is too wet, let it dry out a bit before adding more water. There are many different types of mortars used for various purposes. A dry mortar is exactly what its name implies: there is no added water. It can be used anywhere concrete would be suitable because it has the same properties as that material. A wet or liquid mortar includes some type of liquid such as water or an oil based product like polyurethane. This allows you to work into the mixture without making a big mess.