You wait to do laundry until the very last minute
There’s nothing wrong with doing the laundry as seldom as possible, to save money on the water bill and avoid water waste. But when you constantly run out of clean clothes to wear and end up taking clothes from the washing bin to wear to work just because you want to save laundromat quarters, you’re not saving, my friend, you’re just a cheapskate.
You reuse bags too many times
Sure, you can reuse plastic grocery bags once or twice but when they end up having holes and your risk your food spilling all over the pavement, that’s when you need to stop with this frugal habit.
If you usually pack your lunch to work, just use a proper lunch sack instead of a plastic grocery bag. You can find cheap ones during back-to-school sales. You’ll be able to use them for a longer period of time than grocery bags, plus your food will be properly and safely stored.