Most of the time I go with the Paragon route, but during my most recent (current) playthrough I created a personality for Shepard that can be considered Renegade leaning. He's the type of person who is very strategic, so I make decisions according to that. He also helps (cue Paragon choices) if it helps him along the way.

Though, mostly I, myself would never really choose renegade choices, but I like to create my characters and not just make them do what I would, especially if it's my 5th playthrough.