Actually, I use round cord (paracord is great because it is so sturdy...550 paracord in 4mm size is perfect & you can find it in stores or here on Etsy), and I use plastic sliding cord-lock clasps. The kind you press a button and slide. like the toggles on hoodies. You can find those here too, like at this shop:
https://www.etsy.com/shop/scrubhatladyThat way, everything is adjustable with no ties, it's comfortable and easy to use, and no elastic.