The ideal situation would be that your bring your model and photo set up to the site when you take site photos, then one would be assured that you have similar light just by orienting the model to the site. When this isn't possible, try to shoot in the same type of daylight using site photos to adjust your model's orientation so that you have the correct length and direction of shadows. If you find yourself working late night the day before, you may try a desk lamp oriented the right direction to get the right effect. When taking photos this way, be sure to take photos varying the position and if possible, intensity of the light.

When shooting, its best to impose a background. Make this a sheet of something that has good contrast so that you can remove it digitally later. I use one of three different sheets of fabric that won't reflect the light. Get right down to the level of the model when shooting. Keep in mind that when you shot the site photos, you're point of view was about five feet from the ground and you were probably looking level to the ground. Keep that scale in mind when taking your photos of the model. The site information should be useful to study at this point.