I have never used that word before. A "hack" sounds to me like suspicious behavior, but it's trendy now!
Newspaper isn't as common as it once was when everyone subscribed to the local paper. There always seemed to be piles of newspaper to be recycled or got rid of somehow. Even if you don't subscribe to a newspaper, there are flyers and sales sheets printed on it. Get your hands on some and try some of these.
Papier mache. Remember? You tear newspaper into strips and soak in water, then add white paste and use it as a sort of modeling clay. When it dries, it hardens and holds its shape.
Fire starter. It's basic. Just crumple a few sheets of newspaper tightly, put some kindling over the top and touch the paper with a lit match. Add wood as needed.
Insulation. Newspaper is an excellent insulation, although not approved for housing because of its flammability. Use it in your shoes, under your mattress in a cold bedroom, under throw rugs or anywhere a little warmth will be appreciated. 8 to 10 layers will make a big difference.
Keep your feet warm. Not only by using newspaper as insoles. You can make toasty warm houseshoes by starting with several layers of newspaper. Put them on the floor, then put your toe toward one corner with your heel toward the opposite one. Push your foot closer to the heel corner, then bring up both side corners over the top of your foot and secure with tape or string or yarn. Bring the front corner up over your toes and the back corner up over your heel. Gather the newspaper together at the ankle and tape or tie. You can cover this with cloth or burlap or whatever you have and you will never have such warm houseshoes.
Use newspaper to create or copy patterns. Whether you're sewing, knitting or doing other crafts, newspaper is perfect for making patterns. If it doesn't work out, toss it and grab another sheet. Use a marker to write without the words getting lost in the print.
Use newspaper to make a template before attempting to cut flooring to fit around door jams or other uneven areas like pipes and fancy work.
Newspaper makes a great, disposable mat for muddy, wet boots and shoes. Keep one by the door when the weather is bad. It's a good mat for the kids' craft projects, too (adults', too!).
Newspaper is a good mulch for between rows of vegetables. You can sprinkle a little dirt over it if you don't like the looks. It will keep a lot of weeds from growing.
Of course, you can dry windows and mirrors with it. You can also use it to polish bathroom fixtures and the trim on your vehicle.
What else? Do you use it for other things? Let us know!