|I wasn't sure whether this should be a tip or a notion, but I decided on this category because the templates are made and not bought. It's so simple you'll wonder why you didn't come up with it on your own.
When you are pressing up a specified amount, like a hem, cut a template from posterboard about 10"-12" long and the desired width. Then press the fabric over the template, forming a crease. If you need an allowance at the cut edge of your hem, use 2 templates--first use the one for the desired width, to form a crease. Then make another template 1/4" narrower. Place the narrower template at the crease you made, then press the allowance over it. (This is a lot easier to show than explain.)
There are many applications for these templates and whenever I make one, I punch a hole in the end and add it to a ring with other ones. That way, I don't have to create a new one each time.
This idea came from the Sewing Workshop patterns and some classes I've taken from its owner, Linda Lee. She uses oaktag or manila file folders for hers, but I had the posterboard on hand and it works fine. Be sure not to use the colored posterboard or file folders, the dye may transfer. But plain white or manila works fine.