Getting your car appraised!!!

I think they need a sticky for this one, to keep the good Auto-lovin people from getting scammed by the insurance companies. Just a thought though.

I am here to ask about car appraisals. If we put our heads together we might be able to accomplish a list of things to do, and not to do, when you have your car appraised.
Besides the initial Kelly Blue Book, what do independent appraisers really look for? Do they check underneath the car for neatness? Do they look for poor craftsmanship? Is it possible that they lower the value of the car when ugly Nick-knacks get in the way, such as your O'Reilly coolant overflow tank? Or tacky wiring jobs in plain sight? What really matters when it comes to appraising a car?
And are you suppose to mention that you have a big meaty cam with your Trick-Flow heads (just a reference) hidden beneath the valve covers? Or your recent re-build with only 1,000 miles?
What about little things? How much value can you gain for replacing that cracked dash top? Or removing the fine swirls in your paint and wheels?

And finally, how are you suppose to go about bringing value into the investments you've made if you have no receipts to prove what the parts are worth? On average, do these people know a little bit about after-market prices? Or is he going to call your $150 Tach, worthless and unnecessary?

I cannot find anything on Google about what the average car appraiser looks for in a car. Therefore I am lost, and I'm sure I'm not alone.
Thanks for any input!