I always had this concept of the "shield" being Kryptonian, something that was discovered with Clark in the ship and added to the uniform, or that added itself to the uniform in a sense. And the shield itself was sort of psychoreactive, initially appearing Kryptonian, with a Kryptonian symbol (probably similar to the "8", and could "change", merging Kryptonian letters into English and mimicing designs. So basically he's looking for a symbol, and this happens:
Clark looks at the shield. He reaches down, and picks it up.
He looks at the design Lana has created for him. We still cannot see it (basically it would be the original, initial "S").
The golden and red shield SHIMMERS and begins to FLOW like liquid, translucent metal, subtle contours rearranging into a familiar symbol to mirror Lana's design, but with an alien flair. Something at once alien and human. The standard of SUPERMAN.
Weird, I know, and kind of techy, but I always thought it was a cool idea in terms of exploring how Kryptonian tech works.