This is how I do it
http://www.PanteraPlace.com/page87.htm Look partway down the page. Now that my car is lower I use a lower screw type jack first to get space for the floor jack. I need to do that on the front and back. To jack up the front I use the outer part of the frame area behind the front wheel well, with a jack on both sides. Do not jack on the bottom of the front valance.