Quarter panels, let's cut em off and put new ones on.

I'm getting ready to do some major cutting on my 71 dart. I would like to know all the ins and out of cutting and welding new quarters.
Any and everything you can tell me would be great.

I can weld thin metal but I'm not a body guy and have never done a quarter, so let's hear what you did that helped and what you did that was wrong?

Thanks for all the time and advice.