(hankies above are from the highly-endorsed DISCHARGE STYLE)
Handkerchief, bandanna, hankie, or kerchief. Whatever you call it, it's essential. I keep one with me all the time, for nose-blowing, glasses cleaning, a rag for when your bicycle chain drops, tying things, bundling things, a headband, or, in the woods, as a sieve (try it - you can even drain rice). Lesli and I both won't go on a cycling outing without at least two handkerchiefs. Keep one in your handlebar bag for all contingencies. Along with a good knife, a bandanna is an everyday necessity.
Try out your bandannas as neck wear:
Or as head gear:
Archival Clothing is thinking about designing and producing a limited-edition hankie. If we keep the price low, would anyone be interested? They'd be made in the USA, of course, and available in a few colors.