Here is a crochet mesh that I usually use for market bags. It's very open and surprisingly strong and why shouldn't it be worn as well? No reason at all, says I!
I didn't use a pattern and I didn't really keep very good track of this one, but I think if you're even a beginner crocheter, you could wing this one.
For the foundation row, make a chain about as long as the scarf should be wide. Single crochet into the 5th chain, chain 5, then until you reach the end single crochet into the 3rd chain, and chain 5 repetitively.
For the body rows, Chain 5 and single crochet into the next chain loop to the end of the row.
For the final row, chain 3 and single crochet into the next chain loop and repeat to the end of the row.