I took an iQuilt class where the teacher said to at least draw out the first row of spirals so your muscles can memorize the movement. Don't worry about hitting the line exactly; it's just to give you a visual cue for spacing. Also, you need to consider whether you want a rounded center or a pointy center. For the spiky center, it can help to stop your machine at the point before spiraling out. You need to hesitate at the point for a second anyways so a full stop is not a huge deal. For the rounded center, I try not to stop until I've finished the spiral.
Also -- one tip for hiding imperfections is to add a small spike between the loops and alternate whether you start at the top or bottom. That way everything doesn't have to line up so perfectly and it still looks good.