A little bit a day
I can't remember exactly when did I started it. I think it was roughly 3 or 4 months ago.
One day, I took out all the $1 coins from my wallet and put them in my office drawer as there are too many coins in my wallet. And for no reason, I continue to put all my $1 coin in the drawer until there are too much and I decided that office drawer is not the best place to put money. So I took all the $1 coins home and still carry on putting aside all the $1 in my wallet at the end of the day.
Don't look down on this little gesture. I managed to save up $130 in 4 months.