I have several cat nip plants in the yard.  As they grow through out the
summer I trim the tops off, hang in garage until fall and plant has dried.
I get some cute material and sew a little square with one end open and fill
with the dried crushed cat nip.  After crushing, I put the cat nip in a
plastic container to stay fresh. Cats just love it.  They chew, suck and
roll on the pouch.  One time I made a bunch and took to a craft show, put a
buck on them..  Sold out in 10 minutes.  A gal asked me to make her 25, she
was giving them to her cat lover friends..  Craft people are usually cat
lovers.  If you have a cat that goes outside, you have to put a little fence
around the plant until it gets bigger.  Cats will chew it down to the
ground.  Once established they don't kill it.  Comes back every
year.......................first year you have one plant, couple years later
you have 3, etc.  Can grow like a weed.  Can grow in pots too.