Use the bricklayer's trowel to finish off your mix. Start by testing the consistency of the mortar. If the mix isn't quite right, add more water or pre-mix as required. To mix on a mud board, use your trowel to make a hollow in the centre of the mixture. Then fold the mortar from the outside into the centre. Once it's all folded in, chop the surface with your trowel to work the moisture down to the bottom. Repeat this process until the mixture has an even consistency.