The ease of getting into remote places has increased as methods of travel have expanded. Photography lighting equipment has become much more mobile as well. Many couples that I have worked with want to get just the two of them into the backcountry for photos, and then have the formal ceremony at a more urban location.
A place that has meaning for the couple always helps. If the wedding is at a less than ideal location, think of somewhere close by that offers an interesting background to help make a portrait of the couple more meaningful.
I always concentrate on two things in outdoor photography, the light and the graphic elements of a photo. Light is usually better in the early mornings and later in the evening, especially on sunny days. In composing an image, foreground interest is very important, so you can draw the viewer’s eyes into the image and lead them to the main element of your image.