Large Ornament
Here a very large tin angel is hung in a gap between branches.

Focal Point
Eight inch gold stars are the focal points on this tree. Here one is dramatically hung in a "hole" in the tree.

Bundle
Open branches are also a perfect place to lay bundles of natural materials -- twigs, wheat, berries, etc.

Silk Flowers
Here a bunch of silk flowers, golden twigs, ornaments, and ribbon are tied together and used throughout the tree to fill in the gaps.

Bows
Wired ribbon bows placed on the ends of branches can serve to "fill in" holes and give a beautiful outline to the tree.