Most people get theirs from hearing someone and trying to emulate the sounds that move them. My concept of sound, for instance, is a clear sound but with enough volume to give the note a certain attack so that there is clarity and strength in the tone and a bit of distortion from those little old tubes being driven. For blues, I don't believe in any effects other than reverb and tremolo. But that's just my opinion, because Jimi Hendrix changed our perception of sound by his use of effects. Now for the meat and potatoes of tone.
Little strings tend to give a smaller tone.
The kind of pick or right-hand finger attack can also shape the tone. These things, I feel, are much more important than the kind of guitar and amp. I've heard Duke Robillard sound exactly like T-Bone Walker with a Telecaster. I've heard Junior Watson sound like Otis Rush with a Silvertone. Also, a great jazz tone can be achieved by backing off the tone pot on a solid body guitar.