Magazine Stickers

Having your magazine Cerakoted then laser engraved is one way to get an image onto your magazine. See my post on themed magazines here, here and here

You could also buy a sticker, maybe use some spray paint....

The ones below are from Vinyl Weapons Stickers

Magskins from Gunskins is another option, at the time of this writing they had 57 designs available:

I found these ones on Etsy, a pack of 6 was just $5

Here are a couple of "Banana Clips" stickers available on ebay

This first one is from Thor's Hammer ebay store

Here is another one, also available on ebay

and the smaller version: 

Another ebay find, these one feature a pin-up model, see them here

Another variation on the banana theme are these Black Rifle Division stickers available from evike

Rapid Wraps also makes vinyl "shrink to fit" magazine wraps....tacticalshit has them in stock with 37 designs available