I have voted for candidates based on their stances on issues, or their party's stances. Or their opponent's.
I have voted for parties without knowing much about the candidates.
I have voted for the lesser of two evils.
I have voted against incumbents when I thought a change was necessary, and against incumbents who I thought were competent. (My dad invariably votes against the incumbent.)
I have voted for candidates I liked personally. I have voted for a candidate I couldn't stand personally, but who I admired politically. Actually, that may be a lie. I'm not sure I ever had the opportunity to vote for Teddy Kennedy. But I would have.
I have voted for people who would make my life easier, or at least against those who would make it more difficult.
I have written in my choice when I thought it the appropriate use of my vote.
Once, I got to vote for someone I liked personally, thought would do a good job in the office and would work well with us, and was by far the best of the candidates. And she even won the election.
I don't always vote any particular way. I think about my choices for each race in each election and make my decisions individually.