How do you be paid a knit headdress smaller? I knitted a head covering and it turns out it's too big....

I knitted a head covering and it turns out it's too big. I don't want to put elastic within because it wouldn't look right. What is the best way to shrink or resize a hood? Does folding part of it over and making a clean seam work or would that create too much of a bump?
Answers:    If it's made out of the right material, you can shrink it next to hot water (no soap). Then place it on your manager so it doesn't change shape or find to small. You can also get it raining (damp) then place it on a lampshade (without touching the bulb) for awhile.
Wash it within "hot" water. <}:-})