Fabric: The best men's slippers are all about comfort, so you want light and soft fabrics. Fleece, wool, and soft leathers are the most common options. All of these materials will flex with your feet and are usually soft to the touch. If you're going for an indoor and outdoor slipper, make sure the material is water resistant. Stick to thicker wools, higher quality leather, and nylon.

Traction: House slippers feature soft soles which don't always have any traction built in. This is fine for the house, but if you plan on wearing your slippers outdoors, look for a rubber outsole. If you have hard wood floors at home, you should have a rubber outsole on your house slippers as well to avoid slipping.

Liner: Winter is slipper season, which means you want your slippers to be nice and warm. Look for fleece or shearling liners that lock your body heat without retaining sweat. Natural wool liners have the added benefit of being antimicrobial, which will fight off odor.

Opening: Ideally, the best men's slippers don't require any lace tying. You should be able to slip you feet in and out with minimal effort. Look for slippers with wider openings, with a backless mule being the easier option of all.