Hi Hojo,
First welcome to the forum, I know you have been here for a little but I have not crossed paths.
I would first suggest, if you find something you wish to post about look for where it has been talked about in the past and post there. This shows you do some research yourself and also keeps the place neat. If it is too off topic for the threads you find, include links to the threads you found some useful info in. Saves us having to read up on the topic again and also lets us know you are trying to help yourself.
Now that stuff is out of the way, you can make a plug spinner out of anything that pretty much "spins". So a spring is normally a good start. If you look at pictures of the A1 plug spinner you probably will be able to work it out yourself. If you download the zip under the link below "drdave" you will be able to find pictures on how he made a plug spinner.
I would just like to add when practicing picking you pretty much never need a plug spinner. I think it is ever rare for locksmiths to need them, so if you do not have one it is not the end of the world.
Best of luck, and please post in the below threads and let us know how you go.
viewtopic.php?t=2482 - Home made Plug spinner
viewtopic.php?t=2171 - DIY Plug spinner
viewtopic.php?t=585 - DrDave plugspinner
Consider me inactive or lurker.