11. Get Yourself A Catchphrase 
I have no problem with the modern Doctors having a catchphrase. I cheered every time Chris Eccleston said fantastic with that huge grin plastered over his face, and the way it was incorporated into his final speech was... fantastic. Tennant and allons-y summed up the character of the Doctor perfectly, although his last allons-y in End of Time Part 2 was more than enough cheese to handle. Smith has had a few, notably ... is cool and Geronimo, which fits with his eccentric and alien Doctor. Having a catchphrase is something the kids can associate with a certain Doctor, like the hair and the costume, and so if Capaldi wants to be one of the best, he needs to adopt himself a catchphrase. He could go along similar lines of joyful exclamations, maybe a wonderful or stupendous could fit the bill. Being a big Jon Pertwee fan, he could bring back reverse the polarity of the neutron flow full-time. How about: that was very dangerous and if you do it again I wont be very happy. No? Count your blessings Im not writing this show.