Pizza and sunshine; what's not to like? If you want to reheat some old pizza outdoors, you can turn any pizza box into a makeshift solar oven.
This tip is admittedly a little silly, but it still looks like a lot of fun. The video above will walk you through the entire process. Basically you'll be cutting a transparent window into your box, and reflecting sunlight into it with a flap of aluminium foil. It won't get hot enough to cook raw food, but you could use it to reheat anything that was pre-cooked, or even to melt cheese or marshmallows.