Let's look at an example...
For any logo design, the first thing to do is talk to the client, in detail. A logo needs to represent them to the world, the designer needs to translate their ideals to an image.
This client was just creating his company from the ground up when he commissioned this logo, but he already had some ideas in mind. He asked for it to have the initials 'RS' with flexing arms. From there I asked him general questions: Was there anything he wanted to avoid in the logo? Were there any logos that struck him as being particularly attractive? Did he have any thoughts about colors? From the discussion things were relatively open. I got to work.
I looked at some images for anatomy, lighting, and posing references, considering a few different poses. At the same time I used AutoDesk Maya to play with various angles and perspectives on a cube, to experiment on the look I was trying to achieve. Maya is not a tool I often use, but it is quick to create 3D layouts.
I found a stock image of a male model that closely matched what I had in mind, and used Photoshop to balance the lighting to suit my needs. I wanted the logo to show definition through shadow, but not be obviously lit from any specific direction.
Balancing out the lighting gave me a more clear area to work with for my vector lines. I took the imagery into Illustrator and began creating the shapes I needed. I decided on a general perspective for the cube, and positioning for letters. I decided on a yellow color scheme going forward to reinforce the focus on construction, and compliment the equipment my client would be using day-to-day.
The logo was beginning to take shape, but I wasn't happy with the look. The form was there, but the rounded lines made it feel too soft, the classic lettering felt cartoonish, and outdated.
So I recreated my vectors, iterating on the same ideas but creating more from freehand and concept rather than a true trace.
First, I reduced the contrast that was being created by the hard lines on the cube, and opted for shading the division instead, and raised the peak to give it a more dynamic perspective. Then I sharpened the line quality of the arms, reinforcing the idea of strength and solidity, and modernizing the logo more. For the same reasons, I changed the font used for the 'RS', and began refining the color scheme. Finally I polished the vectors for the full color version of the logo, giving it a 'gem-stone' look, and making it a much more interesting stand-alone visual piece.
Throughout this process, I worked with the client on corresponding lettering to suit the logo. Good typography is as important as good imagery, especially when logo text and image can be separated in future uses.
Once the pieces were finalized and approved, I created the supporting document package for the client, including versions of the logo in monochrome, grey-scale, limited color, and full color, as well as a basic business card to print directly, for convenience.