There are 2 finishes you can use on your seams besides an overlock. One is a french seam and the other is to use your zigzag stitch on the seam to keep the fabric from ravelling.

Zena, I've been sewing garments since I was about 10 years old, so 30+ years, and while they don't all come out perfect, I get lots of compliments, and I managed to do so without a serger up until the last year or so! I've used the serger on several garments, and while it makes construction faster, I'm not sure I'd say it makes it better. I still like French seams, or using Seams Great.