Is that too much to ask? Girls with frikkin' lasers on their heads?
The hanger formly known as "hammock engineer".
I have found that for a beginner (thats me) cellophane tape works great.
I start the end how I want it and put a piece down. Then about 18in away I roll the hem and pull it tight. all the fabric in between will fold itself and is ready for the amount of tape you want. Tape doesn't leave holes and does not need to be removed when sewing. A good choice for anyone with little experience sewing.
Once its all taped up run it though the machine. I keep everything looking straight by making sure the gap next to the foot is always the same.