I think tip number one when you’re planning any shoot is to do as much research as possible into your location, google it! Look on google images, see if there’s a website for the location that might have a gallery, have a look on google maps, suss out what you’re working with as much as you can.
Double check what the weather is looking like in that area, especially if it’s a long way away, then you’ll know whether to expect sun or cloud and, depending on what time you’re shooting where abouts in the sky the sun will be whilst you’re photographing. This will give an idea as to where to position your models, taking into consideration whether you want them in direct sunlight or with the sun behind them, helping you to be as prepared as possible. Also have a think about the season and how that can change the look of your location, especially if it's in a park or somewhere with a lot of flowers/greenery.
Street view on google maps is another lifesaver, If you can get as close as you can to your location on google maps then you might be able to pick out some good location backgrounds to position your models in front of if you're shooting near a road.
Another way of checking out the area is through social media. Instagram is quickly becoming more and more of a search engine. This means that you can type in your location and see what other images people have tagged from that area. This might also give you some inspiration for poses, backgrounds and compositions.
Have a think about how public your area is, depending on what day you’re shooting, will it be super busy making it difficult to get your desired shots. If you are shooting with people who haven’t done as much modelling or aren’t as confident, busy areas could be more intimidating and distracting for your model making them feel and look more uncomfortable in your images. This is always something to bear in mind when shooting with someone new.
It is also important before your shoot to have a think about whether your location might be considered private property, in which case you may need to require permission to shoot there before you arrive.
It is so difficult to be 100% prepared for a photoshoot and every photographer works in a different way. Personally I often find that I can do as much preparation as possible and still find that the best images from my shoots are the ones were I acted spontaneously and visualised images and interesting backgrounds there and then in the moment. Use that creative eye and don't be afraid to go off script and experiment.