Although not 100% accurate, I use a couple of different methods which of course all depends on age and size.
1. The distance between front and rear legs can be used. Generally if there is a longer distance between the legs can determine a female (due to extra room required to carry babies. Males are generally shorter in distance.
2. Head width is also an option. Females tend to have a narrower head width where as males are broader (boofier). This can be down to a couple of different opinions.
a. Human females will try and tell you that all males are boofheads, but I prefer;
b. Males have a larger brain therefore need the larger head to be able to fit the brain.
Of course, these are just my opinions. :lol:
Daz