Ever wonder how a hairdresser ALWAYS gets a straight part in your hair?
As an exHD I will let yo in on this secret, since it works in quilting also. You take the comb to the back of thehead, place yur index finger at the point - on front of head, and pull the hand with comb in it to your index finger. YOU WILL ALWAYS AIM CORRECTLY AND IN A STRAIGHT LINE!
Quilting tip? Place machine needle at the starting point, place index finger at the point where you will end...wallllllla straight line!