I do sme things that have already been mentioned and some that werent:
Walking, going by bycicle r havin a carpool saves alot on gas money.
Knowing how to fix things in the house and how to make some things youreself saves some too.
Because of my job and my studies i use alot of paper sheets, using them both sided helps save money (first side for official print, when print isnt needed anymore other side for notes etc.
One thing that literally puts alot of money in the garbage bag ive seen often is people not planning and utilizing their food properly. So much food gets thrown away because it was bought though it wasnt really needed or for any other reason. It is very rare that i have to throw any info food into the garbage, if you now how to cook a bit, you can utilise it.
Staying with food, most regional and seasonal fresh foods dont only taste better but are alot cheaper then convenience products wich involve less work.
This lsit could go on and on, ist all just small savings, but they add up over time…..