Define the important dimensions as named parameters and build the model from simple shapes before adding detail. Change one parameter at a time to check that clearances and dependent geometry behave sensibly. Inspect the exported mesh and test fabrication tolerances separately, since a mathematically valid model may still be impractical to manufacture.
This is best suited to makers generating parameterized mechanical parts. Before committing a larger project, account for these trade-offs: requires learning modeling syntax; not designed for freeform sculpting.
