I just dive in and worry about the problem as it occurs. After many dives I know how to avoid them all.
I wash my fabric in hot water and dry in hot dryer. I starch and iron it to death before cutting. That fabric is not stretching.
I solved the inaccurate cut problem by buying a Go and the dies I need for just about any quilt pattern.
If I think a package of something is the exact amount I need, I buy two.
I check online for any corrections to patterns, there is always a correction if the pattern is wrong.