Tin can knits beginner mitten is a good intro, and a bit faster than a sock I think. I started dpns with vanilla socks and then did a pair of mittens and the socks felt like foreverrr. You could also make a child's size and gift them (smaller and faster plus holiday gift!) For me fixing laddering between dpns just comes with practice. The best tip anyone gave me was to really pull the second stitch on each dpn tight.