Peter the Younger wrote:
What I'd really like to see from the Klingons is some sense that they really are the cunning, brutally effective warriors they are supposed to be, as opposed to the idiotic, metalheads/space pirates we've seen over the past 15 years or so. Fighting the Klingons should be terrifying.
The way the Klingons looked and felt in ST:TMP should be revived to a large extent. Make them scary looking again and give them the old TOS attitudes about wanting to take on the Federation and beat it in open warfare.