A lot of the new phones come with features that allow you to turn on and off the screen with a gesture while the screen is off. Although it is very useful, sometimes it can also be very annoying when the screen turns on in your pocket and it starts to do random things.
Other than switching the features off in settings, you can simply flip the phone around when you put it in your pockets so that the phone screen is facing away from you, this way the phone won't turn on by rubbing against your legs.
Another solution is to buy a case with a cover, these cases serve also as a screen protector of some sorts, you should find them in most Fido stores!
** Edited to add labels **
