help with hat making - please!

I have begun making welding caps for my husband and his corworkers. Does any one have experience with hat making?  I am having some trouble getting the crown rounded enough not to have little horn looking things sticking up where the seams don't lie against the head.  I am making 4 panel hats for his coworkers because they are easier to make - I make 6 panel hats for my husband and they seem to fit better (but are harder to make).  I would love any tips or advice any one more experienced than me has!

Here is a picture of the type  of hat I am talking about - it is not one I have made, just pulled from google images.

 

First two things tha come to mind are to make sure your seam is sewn very smoothly with no tiny pivots along he curve. The seond is to trim the seams very narrow afterwards. If they are too wide, the seam will tend to bunch and fold upon itself in places, each time creating a visible bump or point on the right side.

thank you!  I was not trimming seams at all and was, in fact, experiemtning with different sizes by increasing the seam allowances, so I definitely had large seams!

Also, if you press on a tailor's ham or some other curved surface, it will help you shape the hat as you go along.  Good luck.  Hats are tricky!