When I give a seminar, the most popular questions have to do with altering the pattern. It is very discouraging when someone spends the time and money on making a garment and it doesn't fit. Not only is the body of the garment important, but so are the sleeves.
Sleeves can be short, long, cuffed, straight, etc.
On the pattern, you must measure the distance from the top of the sleeve to the elbow. This measurement should match yours. If the sleeve has a cuff, take your measurement by holding the tape measure at the shoulder, around the bent elbow to the wrist. If the sleeve is straight, measure from the shoulder to the wrist, with the arm straight. They can make a difference.