This is a post by Dave Martin on PTC site.
CAD Modeling is both an art and a skill. Over multiple projects, industries, and years, certain techniques emerge as being critical to success. We commonly refer to these as best practices. Let’s look at a few that are essential to product development.
Keep Your Ideas Organized
Both new product introduction (NPI) and sustained engineering demand “what if” work. During the former, you iterate different design concepts; during the latter, you implement change as part of a correction or improvement.
This leads to multiple “what if” scenarios as you save models into new files, to preserve the original designs, and to perform work on unconnected copies.