Often, a single silhouette feels like the final form too soon. When you draw one contour, sketch a couple of seams, and position a button, the page immediately begins to resemble a concept. However, the problem here is that you likely haven’t yet selected the true silhouette. It might simply be the first shape your hand can draw. In industrial design, the external form represents key decisions regarding size, handhold, orientation, stability, visual weight, and usage. There simply isn’t enough room to explore all these choices within a single outline.
The value of silhouette sketching is that it forces you to strip away detail. Once color, material, surface texture, labeling, and tiny details of the interface system are removed, the product must communicate using form and proportion. A tool with a thin center implies a handhold. A loudspeaker with a wide base implies stability. A pocket computer with one angled side might imply a specific direction or motion. If the silhouette is not solid, additional detail often serves as a mask for a poor silhouette rather than a valid design choice.
Novice designers sometimes make every design into a squarish shape with rounded corners because it feels safe. Rounded corners are pretty but do not indicate how the product is to be used. There is a reason why a mini-medical instrument, a kitchen timer, a desk lamp dimmer, and a portable battery bank will not all share the same basic silhouette unless their usage and handling strongly support this design approach. By drawing more silhouettes, you will be able to pose more precise questions. Will the product stand up, or will it lie down? Does the product feel fragile, or sturdy? Can the product be held with a hand grasp, a pinch grip, pushed by hand, or do we want it to be avoided in a hand?
Instead of diving straight into the details, draw six small thumbnails of the silhouette of your product idea at once. Make them simple and do not make them larger than a couple of inches. At first, change the basic silhouette only. Draw one that is longer, another that is wider, a third with a wider lower end, a fourth with a larger handhold area, a fifth with a clearer front end, and a final one with a smoother transition between volumes. Do not try to make them look nice and tidy. Do not try to solve all of the seams and button positions yet. You want to evaluate the silhouette choices before you are absorbed into polishing a single solution.
Once the thumbnails are on the page, evaluate them based on simple design considerations. Which solution provides a clear position for the user to grab the product? Which option has adequate area for the interface interface? Which design looks too bulky for what it needs to do? Which silhouette will be easiest to set on a table, suspend from a wall, fit into a carrying bag, or clean? You might discover that the most compelling silhouette is not the most functional. You may also find that two of the sketches are better combined into a new concept, for instance, the lower section of one design and the clearer handhold of another.
The silhouette does not have to resolve the whole product, but it must make the next design step much easier. Once you have decided on one or two better options, redrawing them as a few inches bigger, you can start adding details, parting lines, roundings, visual textures, and where the buttons should be. At this stage, details have a purpose. They are there to help define the silhouette, not to try and cover up a bad one. Now, the drawing can start to feel more purposeful as you are already looking at the product in terms of what form it should have to be a recognizable product.
Next time, you have a product idea that comes to your mind easily, do not be in a rush to make it into a finished concept right away. Put your hand over all the surface details on the paper and only look at the silhouette of the idea. Is it not clear how the product will rest on a surface, move in space, face a user or fit into a hand? You need more silhouette work here. Stronger product concepts often begin as a line of multiple bad or mediocre silhouettes, not as a singular nice drawing.