For me I found a Buff just didn't work with 2 days of chin growth and was just bothersome. To be fair the weather was not windy and I wore a wide brimmed cloth hat.
Sleeping bag liner. I thought this would solve the problem of needing just a little more warmth from a 20f bag, to prevent going to a zero bag.
Just a freaking hassle to get in and out of, it's just a big cloth sack, and unfortunately, for me, did not provide the warmth I needed. Supposedly adding about 10-15f of comfort.
Although...some of the reviews are great, (that's why I bought one) so it must work for some folks.