Re: Connie's statement I write better on a keyboard, incorporating the rhythms, I am wondering whether anyone else gets caught up, as I do sometimes, in the rhythmic sound of the keys being struck? If I start thinking about this, I invariably start making mistakes as I try to keep the rhythm going.
As to how I think, I'd say mostly words, but there are also "pictures", some of which are ineffable. (hi, var.) With enough effort, though, I can put anything into words because for my job, we had to. For ex., we couldn't put something like, "He looked upset", and leave it at that; it had to include a description of facts, such as "His head was lowered and his mouth turned downwards at the corners".
As to looking at pieces and imagining the whole--I absolutely cannot do this! I need to see the whole thing, or at least a picture of it, first; and then often I can "see" the parts in my head, and how they fit. (Speaking of things I am relatively familiar with, that is: say, toys or furniture. Definitely not a car engine!)