Most of brainchecker's stackable crate model prints beautifully without supports, but the handles are open enough that they need some help. The description on that model suggests that you create your own custom supports, and I was extremely happy with how mine turned out, so I thought I'd share them and save others the trouble of making their own.

I printed the model at 0.3 mm layers, and when I took it off the bed, these stayed connected, but popped off with almost no effort and left no scars behind.

If you print the crate at 100% and place it at the very center of your print bed, assuming that your center is set to 0, place one of these at -76.5 mm and one at 76.5 mm, with the base outside of the crate and the top pointing in through the handle, as seen in the picture on this item.

As of at least Cura 4.5, you can click these supports and click the button on the left with four models to set up Per Model Settings, since you don't need them to be as strong as the real model. I changed the wall thickness down to 0.8 and set the infill to 10%, but they probably would have worked equally well at 0%, and maybe at 0.4 walls. I'd just rather waste that small amount of filament than an 8 hour print.