Some, but not all faded butterfly blooms will make seed pods.
The pods are kind of shaped like tiny skinny footballs. There are numerous seeds inside them. You must wait though until the pod has dried enough that it has started to split open on the tip end. This is usually late Fall, November for my zone.

Not all butterfly bushes make seed pods though. I don't think the yellow one does, and I have 2 different variegated ones that I have never seen a pod on.

The link below (at the very bottom) shows the seeds. They look like short hairs with a little dot in the middle of them.

Store them cool and dry until they are planted.

I was fortunate and several seeds germinated in the flower bed surrounding my bush. I found them among the weeds because I was behind on my weeding, Preening and Mulching last year. The new seedlings are growing like weeds and some have even started branching out a good bit. I need to get them dug out and potted up for sharing or trading later. I can't bear to just pull them and compost them.

Sue...chemocurl

Here is a link that might be useful: Butterfly Bush seeds

Hi, I tried saving seeds from my butterfly bush last year and wasn't sure if it was the actual seeds I was saving. I too am a "newbie". This year I trimmed a stem off the bottom of the bush, took off the bottom leaves and just stuck it in the ground. Kept it well watered and it is growing. It has a lot of new leaves and a flower beginning. It's worth a shot.

Barb

I can attest, that does work well. I've grown about 5 new plants from mine as gifts to gardening friends. In the early spring look for a 3-5 inch stalk growing out nearest the ground on old wood. I also add some rooting hormone in liquid form. Good luck!