Now that I've made four hats from Simplicity 4083, I confess that I have not learned the secret to easy, great-looking hats. It is safe to say that this hat is perfect for costuming/cosplay and it is quite possible to cover up little imperfections with feathers, flowers, ribbon, etc.
The first hat was made following the pattern, size small. I used acrylic felt for all the hats as wool felt is not available in retail fabric stores here and I imagine it costs more than I wanted to spend on a test hat. I used heavy weight fusible interfacing and was not altogether thrilled with the flexibility in the crown of the hat. The top and brim seemed pretty stiff, for their intended purpose anyway.
In an attempt to further stiffen the crown and solve the problems of "dents" or small sags, I tried Aleene's fabric stiffener that I bought from JoAnn Fabrics. I could have diluted it with water, but not knowing how it would turn out, I used it full strength. It seemed a lot like runny, white school glue. It did dry clear and it did stiffen the fabric. So A+ on that account. However the moisture caused the acrylic felt to pill. The stiffness of the fabric did not allow much give at all, so I wouldn't recommend it full strength if you want something soft. I tried using a stiff brush to smooth out the pills, but all that did was make the stiffener flake and turn white. I have not resolved the texture issue, and was planning to try a razor blade or something to try to remove some of the pills - but the hat has been donated for use as a prop. Next time I will also try applying the stiffener to the inside of the hat, so the look won't be so much of an issue, maybe. Since the inside was covered with interfacing, I couldn't tell if the reverse side pilled as well.
Since I could not achieve that perfect stiff hat look with the glue stuff, I decided to try craft weight interfacing. Pellon Peltex 70. I've used this before in a collar and it worked nicely. It is $6/yard, so a coupon is great for this (but not at Hancock since their coupons expressly exlcude interfacing). The hats were stiffer, but since Peltex is a sew-in and not a fusible, there were a few dent-looking areas in the crown, but not as many as with the lighter fusible interfacing. I shortened the crown about 2.5 inches to look a little better on a female and also used size medium for a more comfortable fit for the three females wearing the hats.
While this process did not create a professional-looking hat, the hats were easy to make (less than a day per hat) and folks seem to like them. It took me until the third hat to realize that pinning the bias tape on the brim while slip stiching is much less painful on the hands (duh). The hubby is now patiently waiting for his hat, once I recover.