Probably so many things… like we know that plastic is not so good, but we still make products of it and buy water or want ever in plastic.
Air conditioners are not so friendly but we want cooler air. In glamping sites you even can find it in the tent.
When it comes to driving we drive more than nesessary, just because it is more comfortable.
While having holidays we especially relax and use single use products.
Food waste, I believe many households still have quite an amount of it. And it takes just a little bit of more planning to solve it.
Or like new phones, laptops or any kind of electronics which still are good, but we want the last versions.