There are a few things you may get away with skipping in the dressmaking process, but transferring dart lines form your patterns to the fabric pieces should not be one of them.
Let's start with the fact that darts are the building blocks of a well-constructed non-stretch garment. Darts are placed at key areas on a garment and have a very precise placements, radiating from higher points on the front and back. For that reason, dart lines have to be transferred to the garment pieces exactly as they appear on the paper pattern.The lines are then following in construction process to fold and stitch the dart as accurately as possible. Following precise dart lines will ensure the garment not only looks well-balanced but also feels and fits comfortably,
Dart lines are always transferred to the wrong side of the fabric, never the fabric's right side. This not only preserves the garment's right side, preventing it from staining and permanent damage, the dart is always folded form the fabric's wrong side which makes it much easier to fold and stitch following designated lines if they are placed on the wrong side.