Improvising with a Broadsword a few years back.
I'm using movements from the two Broadsword forms that I know, along with some other weapons basics and blended them to get this 'flow' up and down the room. If you practice Broadsword, give it a try.
*Remember when improvising it does not have to be 'fancy'; The KISS theory!
The point of improvising is to get 'rapport' with the techniques in various directions and to keep it flowing in a variety of sequences.
One of the problems with forms is that techniques can get locked into a specific order. To be able to actually use the techniques they must be able to be preformed in any order and in any direction.