Next, you'll need to consider how often you communicate. Emailing and texting might not be super intimate, but if you're doing it all the time, your relationship could definitely be slipping outside the lines of platonic. Do you find any excuse you can to text your friend? Do you email them when you discover something just a little bit funny online or you have a question about "that one movie with that one guy..."? Are they doing the same? These are big clues that you want to be more than friends.
Paying attention to how you keep in touch with a friend is a great way to see if you might want to make out more than just hang out. Keep tabs on how you keep tabs on each other and you'll be one step closer to determining where you stand.
After you've considered how you communicate with your "platonic" friend, the next part of your relationship to examine is your level and nature of physical contact. In other words how often and where do you touch? Body language holds many answers for friends who might secretly want to be more.
First, ask yourself, how do you touch? Does your friend find any excuse to touch you? Have there been many times that they've "accidentally" brushed your arm or leg, or touched your hair? Do you find yourself doing the same? If so, chances are that there is some physical chemistry brewing under the surface. If you're unsure of where your relationship stands start paying attention to how you touch one another and you'll likely find some answers as to whether you are more than just friends.