Stokinette Baby Onesie fits a newborn to a few months old babies depending on how loosely it is knit.

It is worked in stockinette stitch.
I have specifically used Alize baby Sekerim for this project, you can use a similar yarn quality to get the same results.
You will need a single color of yarn.
Details are mentioned in the pattern.

The pattern includes a Romper and two Cap styles, along with the knitting techniques.

It is a printer-friendly pdf. You can print or use the pattern digitally.

Happy Knitting!