The Rockler Lid Support ($11.99-12.99) that @huntsworkshop used to build her grandson's toy box is designed to close slowly and also has a “lid stay” feature that keeps the box open at 85 degrees. I am. There are three foot-pound ratings based on the weight of the lid. If you use a little too much force, the lid will not close automatically at most angles. Supports come in left-mounted, right-mounted, and center-mounted options, and you can fine-tune your support using one, two, or three supports. This gives you the right amount of closing resistance for almost any lid. Rockler has a handy formula for calculating this on their site.
If you have kids and have seen these eyelid supports, you've already made objections like, “My kid's going to break his finger before the snack cabbage patch doll bites his finger.” You may have one. This is another place where @huntsworkshop's genius shines. We've found that piano hinges are perfect for everything from creating a bench with storage under your seat to hiding a secret room under your IKEA loft bed. @huntsworkshop knows that too and installed a piano hinge on the back of the lid so it can open and close without breaking, keeping my little brother locked in for years.