try one of these two methods... an eastern european version is sort of an upside down 'pot' style...the sides of the hat are one straight strip. join ends after deciding on a length...24 in is large... and you might want that unless he has an exceptionally small head for a guy... i say this because his skin will be sensitive and he probably won't want it to be tight at all... the top of the hat is a circle made to fit the cylinder you have created. it is a very common and more masculine style than lots of hats... personally, i would make the 'cuff' (sides of the hat) long enough to be double all the way back up tot he crown (kind of like sewn on ribbing). this way there is no seam to rub his skin... now include enough to turn up for a cuff and it will look almost russian.... here's a pic...this one looks too big for her but it's the style i'm talking about...and i think it should be easy to do as it is one flat pc and one round pc....and of course, this one doesn't have the turned up cuff...but that is easy to do...
and the other thing you can do is cut all the fleece into 1/2" strips and knit with them..i have done this as well and it is really soft, but you still might not want to have it knitted...