Watch the Strategy 2: Work the Style online guitar lesson by Jon Herington from Ear IQ: Soloing Strategies
Sometimes the single most important thing to address when coming up with a solo is the style. Often a job is even presented as centered around a style. I'll get asked, "Can you play a Rockabilly solo?", or someone will say, "Play this like Wes Montgomery", or, "I need a Stevie Ray sound", etc. This is similar to character, of course, but it's definitely a factor that I've had to deal with and I still do that even when I'm making my own records, since style is such a powerful thing. It also can make life easier for you, since if you identify the style of playing a song requires, it helps you make choices that are likely to be the right ones for that song. Of course, you have to be somewhat familiar with that style for this to work. But even just a passing familiarity with a style can direct you to places you might not ordinarily go, and they're likely to be a good fit for the song.
The second solo we're going to look at is from one of my own recordings, and it's called "Thirteen Feet of Rain". Let's take a look at the track.