Look beyond the preview image
Check the model’s dimensions, required hardware, assembly instructions and photos of completed prints. Read comments for fit issues and check whether the designer has published a newer version.
Keep the licence with the file
Downloading a model does not automatically permit every use. Record its source URL, designer, version and licence. Review whether the terms allow modification, sharing and your intended commercial use.
Creative Commons licences use conditions such as attribution (BY), share-alike (SA), non-commercial (NC) and no derivatives (ND). Read the actual licence and any additional terms. If your planned use is unclear, ask the creator.
Useful places to start
Printables and MakerWorld are places to browse models. Review each model individually. For something personal, tell us your idea or design your own.
Keep exploring
Want to go deeper? These official guides have more detail.