Goddammit, they're klingons, they need MONGOL BEARDS!
I'm usually all for more variations for Star Trek species. But klingons without mongol beards just... don't look right. Even General Chang - the baldest prime klingon - at least had some hair.
Giving each klingons a different, Samurai - inspired warrior hairstyle would also have been a nice way to quickly introduce different characters. All these bald guys look pretty much the same.
There is concept artwork for the Into Darkness klingon on the web which is basically the exact same design - but with hair. It makes ALL the difference!
Saru didn't really stood out for me, he looks like a typical Voyager alien. But the concept on the left looks actually interesting. Saru seems a bit... grumpy... with all those rills and wrinkles.