One of the best tips given for those who want to save cash is to avoid using all forms of digital money. People have a much harder time keeping track of purchases when they don't actually see money coming and going. You see this all the time on debt shows, where people use their credit and debit cards for everything and have no real idea about how much their spending. It is even worse when it comes to online shopping, where you have neither a product nor cash to ground your spending.
If you want to make a budget and stick to it, leave your cards at home and use cash.