Wouldn't it be great, to have an idea and to be able to realise it fairly directly? Perhaps even the smallest flash of inspiration can lift one out of the maybe particularly dull reality. If one can then also inconspicuously continue to work oneself along, well, that's almost a gift.
One doesn't need a high-tech device like a smartphone or a computer, all one needs is a small sketch-pad and a pencil. It's no problem at all, if you have to later transfer your text or design, you'll more than likely improve it anyway. If in fact you have a choice, try doing your work in turbulent surroundings, e.g., in a bus full of school-kids.
There are in fact designers, who maintain, even in this day and age, that creative work can only be done using the customary method. Since what actually happens, is that first of all, one holds on to one particular idea before the next one comes to light. One should try to avoid having a stack of vague ideas, putting them to paper in the customary fashion is simply much quicker.
After all, in the end, all you want to do, is be reminded of your original thoughts. Sometimes they have even matured and come back to you in a more suitable form. By no means everything can be realized directly. To be able to pick up the idea again, one probably has to be in the same mood as one was in when the thought occurred. Adapting oneself to more professional technologies too soon, may even destroy the inspiration.
Of course, as far as motor car technology is concerned, drawing on pure creativity from an undefined fountain of ideas is hardly,- or even not at all what's wanted. In this case, it's more about how things are to be applied. Already with the first sketches, the creative path is sometimes defined right from the word go, e.g., through the presence of what already exists. Whether the designer likes it or not, that's where he/she has to pick up the thread.
Perhaps the area and the direction have already been decided on. In this case, there may be less time necessary for the finding, than for the realisation of an idea. It's not only a matter of oneself being satisfied with the sketch, it is much more important to be able to convince others. Remember, the larger the amount of creativity is, the more likely it is that competing teams are going to be put together.
In the meantime, as a reader, one doesn't see all that big a difference between the expressive possibilities of longer advertising text-blocks and illustrations. The former has developed so quickly, that one could almost even speak of abstract texting. Some texts are only designed, for the reader to be able to identify him-/herself in the advertising. 03/12