It's the same fundamentals as tanking /warrior - macro Enmity for JAs, TP/WS in DD gear, haste for flash, PDT/MDT oshit builds, etc, etc.

Macro in a little more fast cast / shield skill into Ichi and Haste into Ni. Ex: Creed Armet +2 for Ichi, full Haste helm for Ni. Since /nin Ichi & Ni are 3 shadows/each, I tend to idle Ichi shadows whenever I cast between fights.

If you aren't familar with the basics of Utsusemi: Ichi overwrites Ichi, Ni overwrites Ni and Ichi, Ichi does NOT overwrite Ni. If you start casting Ichi before you lose your last shadow tho, because of its long cast time, you'll get shadows back up just after the mob attacks and takes the previous one. Use Reprisal or Rampart (if you have Iron will merits) if you find yourself having trouble to get shadows up in a tight spot.

As the old saying goes: Paladin doesn't evade, the monster whiffs. You can rely more on NOT evading to time shadow casting than you can evading. It takes some time & practice to get a good feel for how to use shadows, but it's the standard of how endgame paladin has tanked for years.

One of the big things to remember is this: You can blood tank on Pld/Nin if the situation calls for it, you won't lose out on much except Fencer/double attack by not having /war. You cannot shadow tank /war, so you can't throw up shadows to absorb a huge nuke, or avoid getting hit by additional effects / colossal DPH. This is why I default to /nin on Pld.

Really tho, I don't find playstyle between pld/nin and pld/war to be much different, but that may just be me, since I've always played the part of a hatemonger, not a turtle.