This cute side opening romper is made from the top down using herringbone half double crochet.

Materials
dk / weight 3 yarn I used Hobbii Rainbow Cotton 8/6 105 metres per 50g which states 4ply but its like DK
3.5 and 4 mm crochet hooks
6-8 x 15 mm buttons

Written in English US terms with abbreviations for UK terms

The PDF is 22 pages with plenty of photos.