After looking at lots of amazing ornaments at the William Morris exhibition, I decided I should look into his books and patterns some more online.
I like the way berries have been used to cover up space below, something which could work well when working with curved leaves within a box-tile.
The use of a centred ornament works really well with a border of a similar density:
The leaves and the flowers are the most appealing in the below image:
Some more flowers with a similar form:
The curvature of the leaves work really well in the border below: