1. You can use mosaics to create interesting artistic effects. For example, rather than cropping your finished montage, you can leave it as it is, with all the component images clearly visible. This works best if you select an area of particular visual interest and create a cluster of shapes around it.

2. To emphasise this 'jigsaw puzzle' effect, you might like to try experimenting with discreet borders around the individual shots. If you don't like the effect, you can always reverse it. Remember that this is art, not an exact science, so feel free to experiment until you get the effect you're looking for.