I have a eucalytus but I keep it pruned and it stays bush-sized. When the leaves are young, they are round-shaped, and as the bush matures into a tree the leaves become elongated.
If there is a branch or even a twig on your eucalyptus where the leaves are still round-shaped, you can take a cutting from this in the normal way.
Cut a few inches at the end of the twig, snip off the extreme tip, remove excess leaves, dip in rooting hormone, and plant in a small pot filled with compost. I like to put a clear plastic bag over the pot to mimic the humid conditions of a greenhouse, but eucalyptus is used to arid conditions in its home setting, so this is probably not necessary.
Keep the cutting overwintered in a frost-free environment where there is plenty of light, and by next spring you should have plenty of roots, and a nice young eucalytus plant.
Once established, they grow very quickly, as I am sure you are well aware.
Good luck.