Leaning on the accurate model produced for the dummy object, sketch out ideas for the watch body design and take notes how you design references the electronic parts.
From hand draw notes to vector-based illustration ready to drop into your CAD application, any pathway you find to capture your ideas to aid you during the 3D modeling process is acceptable. However, when making a tight enclosure for electronics I find it is helpful to do your sketching at this stage in the order: after creating your "dummy" object.
Identify Where Your Design Interfaces wIth DummyWhether you will end up using a digital tool or a pencil and napkin to get down your ideas is up to you, but the most crucial information for you to consider at this stage is how your design will interface with your electronics.
After I completed the dummy design stage, I had an extremely accurate vector model for the TIMESQUARE electronics -- necessary given that I wanted the electronics inserted into my design. I planned for the prongs off the top and bottom of the PCB to hold the watch in place -- meaning that measuring and modeling the PCB itself (for the outer ridge) was the most important information and became "sea level" in my design file. The buttons, likewise, were to be centered off the side of the PCB.
Commit to a Design ConceptThis step is a matter of taste, but one that has stood me well over the years. When you are designing your project, commit to the one design element that is the center of why you are designing the project -- and stick with it. If you are familiar with games design, the concept "What is the X?" applies here.
For Circling the Square, my essential design goal was to transform the edgy, rectilinear construction of TIMESQUARE into a "soft" rounded shape much like a that could also function as a pocket watch. Even when distracted by a host of unusual extrusion tools, I stuck to my guns and rejected the version of the faceplate that didn't match this goal.
Trace Sketch with Vector Illustration Tool For Reference Markers for 3D Modeling.Working within digital tools for this stage is a pretty helpful hack. After using a pencil tool or similar to quickly work out ideas in a layer over the orthographical views, I created a new layer to trace with vector-based tools around the contours with careful, closed loops.
These layers can be imported into your 3D design software and used as references -- or even extruded into surfaces -- to help you create your 3D model!
Break Down Complicated Shapes Into Primitive SolidsWith the Circling the Square design, I created a few overfed ellipsoids and overlapped them, keeping the angle for much of the curved surface at a nice low angle that desktop 3D printers excel with.
You can building organic shapes from simple primitives, curves, lofting, and rails keeps the complexity of the model comparatively low, allowing for better control over adjustments. By breaking complex shapes into systems of cylinders, spheres, cubes, and pyramids you will help yourself find a way for these elements to be quickly constructed in the modeling phase.