Pictured are 2 muzzles that are roughly blocked out using this method.

This is how i block out a muzzle!

1. Get a 5 inch thick block of foam, scissors, (electric knife if you want) and a sharpie

2. Draw out the profile, then cut the block past the drawing (still a square form, drawn on profile still visible)

3. Draw where you want the lip split to be and other details, begin refining

4. I tend to squish the foam to make it look the way i want, then cut it away to copy the way i squished it. (if that makes sense) :P

5. From there i basically have the shape i want, so i carve out the inside of the mouth to hollow it out

6. After i have it blocked out i attach it to the face, then finish refining