The site is in Finnish - used dried stems of Deschampsia cespitosa (tufted hairgrass) and string this snowflake/star together with thread (not sure what to use for a needle). The author says that straw is too thick.
Himmeli, straw crafts with symbol meaning and often made for Christmas. A popular tradition in Finland since ages. This book by Eija Koski newly launched with all sorts of himmelis, both for modern and traditional interior.