Never lose sight of what you're supposed to protect.
Ever.

When you really want to punch something,
you really probably shouldn't.

Always assume a worst-case scenario.

Use the dead as a stepping stone,
but be sure to die a stepping stone yourself.

When the tongue slips, grab it,
and yank out the truth.

Haste makes waste.

The truth hungers to be free.

The more irrelevant something seems,
the more relevant it's bound to be.

Use the lights to your advantage.

Dıck Dictum #116 is briefly mentioned during Achi's (failed) interrogation, but unfortunately Kano never reads it out loud, so we'll never know.

The last Dıck Dictum we see in the story is #117:

Get'em when they're tired.

In the previously mentioned interrogation scene, Kano is desperately flipping through his diary for Dıck tips on how to interrogate Achi, and it ends shortly afterwards, meaning that Dictum #117 is most likely near the end of the diary. While veiny and black, Kano's Dıck Diary doesn't look particularly thick and fits comfortably in one hand, so it can't be too big, definitely under 300 pages.
Considering the points above, we can assume that Kano's Dıck Diary is ~120 dictums long, which would translate to ~200 pages since a lot of dictums (if not all) are written on a two page spread.

And that's it. If there are any Dıck Dictums I missed, let me know, I'll add them to this list.