Wire and Tape Method
I add leaves to the bottom for a finished look.
Twist and pull the ivy and ribbon loops downward if needed to conceal the bottom stem.
The excess ribbon length can be snipped back once the corsage is finished to more manageable lengths.
Here is the back of the corsage design, flattened and ready to lay gently against a shoulder with no stray wire ends poking out.
Fill in any gaps with the remaining leaves, bending if needed to conceal design elements.
Press the base of the leaf between your thumb and forefinger before bending, giving support so you don't tear the leaf.