Warmth and CA-block. Keeping hands warm and dry is the thing everyone should do. I think in terms of drug prophylaxis or for diminution in severity of the raynaud's, calcium channel blockers are the best therapeutic option. I favor Diltiazem over verapamil (less constipation and slowing of heart rate), and over Nifedipine and amlodipine (less edema). However, all are fine and work. Others may use nitroglycerine paste.
See below. Raynaud's phenomenon describes a set of color changes in response to cold or stress. These are usually preventable and treatable. Poor circulation does not have those changes.
Color and location. Raynauds causes fingers to turn either white, blue and/or red usually in the cold. Poor circulation is different because it can affect palms and usually the border of the color change is a smooth transition. Raynauds usually has a distinct line between normal and blue /white.