A good pressing with light starch and a hot iron can make the difference between "home made" and "Handmade" on most any sewing project as well as
The side seam of the apron I was making was cut on the bias which is notorious for getting all funky wavy when being sewn, it is the nature of the bias-beast. But it is nothing that can't be tamed with an iron.
1)Wavy seam - sometimes in the quilting world this would be referred to as "friendly"
Heat up your iron but keep it dry.
2) Spray the wave with a liberal amount of starch ( must be starch) and then gently pat the seam until it lays down flat. Starch makes fibers seize up and that will get rid of your wave!
3) Press flat - don't iron.. ironing goes back and forth.. pressing is up and down.. heat-lift-move-press again
Want to see how to work this magic on a wonky quilt block?.. you will be amazed!