I have found the following to be the teaching from Dogen I have found the most helpful and remember the most frequently:

"You should therefore cease from practice based on intellectual understanding, pursuing words and following after speech, and learn the backward step that turns your light inwardly to illuminate your self. Body and mind of themselves will drop away, and your original face will be manifest. If you want to attain suchness, you should practice suchness without delay."
-Fukanzazengi

I had a bit of an "a-ha!" moment with this last July, thanks to reading a talk by Geoffrey Shugen Arnold in The Art of Just Sitting (pp. 167-173) featuring similar instructions from Yangshan ("Reverse your thought to think of the thinking mind") while on an intensive solitary retreat. It's only deepened since. And I've found that this is a more effective and direct way to still the mind than actually trying to still the mind. When, instead of watching the breath or whatever else, one simply turns awareness toward the activity of the thinking mind, it is remarkable. The mind cannot sustain the same degree of chatter under the fire of attention.

And, as someone who experiences bliss on the cushion from time to time, I find that this practice brings almost immediate sensations of bliss. And I'm not talking about something occult. It feels good in the same way it feels good to set down a heavy load you've been carrying a while. It's just that in this case it is the load of self. The chattering mind does not have to grow perfectly quiet for one to experience stillness. One just has to look at the mind that looks, think at the mind that thinks, and this simple self-reflexive act creates an enormous sense of spaciousness and well-being. Not to mention shedding light on the process of self.

"The zazen I speak of is not learning meditation. It is simply the Dharma-gate of repose and bliss, the practice-realization of totally culminated enlightenment. It is the manifestation of ultimate reality. Traps and snares can never reach it. Once its heart is grasped, you are like the tiger when he enters the mountain. For you must know that just there (in zazen) the right Dharma is manifesting itself and that from the first dullness and distraction are struck aside."
-Fukanzazengi