Picture a house without disposable items. It is only recently that paper plates and cups became a household fixture, so let's change it back before it becomes a habit. Plastic bags are a recent innovation, and they are already banned in many parts of Europe to reduce waste. Don't buy single-use items, period.
Carry a reusable water bottle rather than buying water while you are out.
If you have a stainless steel or aluminum bottle with you, you can quench your thirst without wasting a plastic bottle. They are lightweight and easy to transport, and they are cool to look at -- from classic solid colours to bright modern designs, there is a perfect design for everyone! Plus, they can be recycled if it ever breaks. Reuse and recycle your water bottle. You can't beat that.
Use a reusable shopping bag.
Why use one? The question should be, why shouldn't you use one? "Paper or plastic" is an outdated choice; it's now "canvas, netting, or recycled plastic". No matter which you prefer, it's the right choice! They're lightweight, strong, and durable. Bring your own bag every time you go shopping and see how few bags are stashed in your cupboard at the end of the year -- and how much plastic you can keep out of the landfill.
Take a snack while you are out and about.
Instead of stopping for fast food, take out a container of your favourite trail mix, granola, or fruit. It's good for the environment and your waistline!