Well if you're just looking for 'standard' stickers for now (with the more creative ones to continue to be fleshed out in this thread to be ordered later), here are the official logos: https://www.kde.org/stuff/clipart.php. Just order some approved quantity from a sticker supply company using the approved logo. Presumably, you would send them the hi-rez file (https://www.kde.org/stuff/clipart/klogo-official-oxygen-3000x3000.png) and have them make some up. I would love a few of these myself. Although perhaps someone needs to chime in and over-ride me here, because I would expect that with Plasma 5, the logo may need to be updated.

Yes, those are the old oxygen logos. I thought we had newer art like what is in the K menu in Plasma 5 somewhere that could be utilized to create stickers. Anyone know where such images can be found or want to take up creating them? I guess posting to that url would be good once they are completed.