This sweet little set would be suitable for the Spring baby. Baby Rompers and jacket - which is a sideways knit - is completed in simple garter stitch and would be suitable for the advanced beginner knitter. Minimal seaming is involved.
An interesting 'accordion' dress concept I saw on a Chinese dress site people might be interested in (link to dress in comments) : sewing. It would be interesting to not too a bunch of colors for the accordion part, but just one.