As for the 3DS, it's as simple as a few tabs on the Mii Maker, and it outputs your Mii on your SD card.
As for the Wii, I'm using EasyCap USB (a TV Console Capture Device), then I Print Screen that, and I crop it in an photo editor.
A lot of mine are just useless Mii's, such as Happy Guy, Bad Guy, Sad Guy, ect. I also have a Ninja Dog. Unfortunatly, I can't post any Miis, as I don't know how to.