I am working on a garment needing both sewn and serged seams and am still perfecting my serger skills. I am on my 3rd muslin now and have loads of weird fabric scrap shapes. Suddenly I had a light bulb moment- use the scraps to practice serging!
It holds my interest because each scrap has various combinations of inside and outside corners and curves of varying degrees. Instead of clipping some of the inside curves and corners I used my pinking shears and was pleased to find out how well it let the fabric ease into a straight line in some instances.
Having curves and corners of various angles and degrees on different fabric types has opened me up to knowing which ones I am doing OK on and which ones I need to work on.
I kept thinking one day I would sit down and do more serger practicing but just never seem to get around to it. Now practicing is fun, I don't need to set aside a block of time or configure my serger for a particular stitch. I just pick up a scrap, take a break from the sewing project and improve my understanding of a serger technique for whatever threading or stitch it is set up to do!