Here's a handy little tip to keep in mind when making holiday centerpieces. Pomps (daisies and cushion mums) in fall colors sometimes have long single stems with short laterals (flower heads with very short stems) shooting off them.
They are sometimes just too short to use effectively without lengthening the stem.
Don't discard the long single stem part that you cut the laterals off from. Instead, you can cut it into lengths and then, after cutting the short flower stem cleanly with a knife, INSERT into the hollow bigger stem portion.
Take care not to crush either of the stems. Moisture has to be able to pass up through the flower stem and travel upwards to the flower head.
Without this little "extension", this bronze cushion pomp wouldn't have extended long enough to be at the outer end of the arrangement.
You can see from a top view that the bronze colored mums are now distributed evenly on all sides of the arrangement - the outer flower heads extending just beyond the leather leaf fern tips.
Note how in the upper right, I've clustered small lime green button mums. This balances the color of the large green spider mum, yet gives contrast of size and texture.
Smaller flowers can be grouped in clusters for more impact and interest in this way.