The easiest and most effective way of contouring is with a brush and either solution in a small container to brush in, or preferably with a mousse as it is easier to apply. Once you have finished the spray tan and it is dry, just dip the brush in the solution or spray the mousse onto the end of the brush and apply to where you want to contour. An easy way to start is with the face, just brush in the solution onto cheekbones in the same way as you apply blusher. This will give you a "hollow cheek" effect and, if you are using good solution, it will still have this effect once the colour guide is washed off and the tan has developed.