Here’s one that is very useful for summer sewing. When making certain garments, like camisoles, I use fold-over elastic to bind the raw edges. This gives a bulk-free finish that looks very RTW. To do this, remove the seam allowance from the edge to be bound. Then, fold the elastic over the trimmed edge and stitch using a narrow zigzag stitch (I use 1mm width on my Pfaff). Don’t pull the elastic as you sew. You want a 1:1 ratio of length of elastic to garment edge length. If you are making a camisole, or other spaghetti-strapped piece, you can then extend the fold-over elastic to create the straps. Here’s a (not so great, sorry) picture of a camisole I made using this technique.
Happy sewing, and Happy 4th of July to my fellow Americans!