Having made umpteen million test fit muslins (seriously. 20 years worth, still working on it), I have come up with a fast and accurate method for sewing darts. This works for the regular pointed dart like a shoulder or bust dart, as well as the double pointed 'fish eye' dart.
For this method to work, you'll first need to mark the center stiching line on your machine. I drew mine with a fine sharpie, but you could mark it with a sticky note.
Next you will need to mark the dart. To do this, use two small clips for the dart ends and a small drill hole 1/2 inch from the dart point. To mark the drill hole, use a machine needle and poke through the two layers of fabric. You do this a half inch away from the dart end because otherwise the hole might show through.
Next align the marked ends of the dart together,and fold dart along the dart fold line, marking with a pin at a half inch past the drill hole.
Next sew the dart, but here is the trick:
Sew the dart aligning the end of the dart with the center sewing line.
Keep sewing, watching the pinned end of the dart and making sure it falls exactly on the center sewing line.
Finish by stitching exactly to the end of the dart. Then stop with the needle down.