Sustained eye contact usually begins with furtive glances across the room. If you find yourself sharing long looks with another, that is a good sign your attraction is mutual. Once this first look is shared, evaluate whether it is simply a coincidence that you happened to look in the same direction, or maybe something more.
Short eye contact is another identifier for attraction. Does she look away quickly when you catch her watching? This is a big sign she could be interested but just a little shy. Another way to tell is if you notice him looking at you frequently but for short periods of time. Goes to show that eye contact does not need to be sustained to signal attraction.
This can be anything from a gently bump of the shoulder to hair play. Nothing creates a spark like touching each of for the very first time. She might push your hair out of your face, or scoot closer to wipe a leaf out of your fringe. Sometimes men will place their hand on your back as they let you through a door, or lead you in a certain direction. This is derived from a dominating gesture meant to make the recipient feel safe and in good hands.