I've always put rubbish in my pocket and kept it until I can find a bin after seeing a Sesame street segment about it as a young kid.

But when I smoked I did sometimes drop my butts on the ground. Normally I would keep hold of them if I was near a public bin as most of them have ashtrays in the top I could dispose of them in.

Coincidentally I've noticed that l, at least locally to me, the council have replaced those bins with ones with no ashtrays which has definitely increased the number of butts on the ground. Wonder if having them is seen as encouraging smoking.

But sometimes if I wasn't near a public bin I'd drop my cig, stub it out and leave it on the ground. I used to smoke hand rolled cigarettes with no filter, just tobacco and paper. I justified it to myself saying it would biodegrade but it still can't have been good for the environment.