So smush it properly with your shoe and then put it in your pocket until you get home or find a worthy receptacle. If I have a granola bar wrapper in my hand an

So smush it properly with your shoe and then put it in your pocket until you get home or find a worthy receptacle. If I have a granola bar wrapper in my hand and there's no trash cans nearby, I don't throw it on the ground; I hold it in my hand/pocket/bag until I can dispose of it. Cigarette filters are not a special case in this thinking.