Hey guys.
This is my build for Jarvan IV, played as a Tank/DPS.
I want to play him as a Tank/DPS because of his initiating capabilities. He is good as an initiator and therefore needs to be able to take some damage.
In this build you will see, that im focusing far more on the Tank side, than on the DPS side, but even then he can still do very good damage.

Thanks for watching, hope you guys enjoyed, and good luck in the Field of Justice. :)

My rune choice is quite simple:
I take Greater Mark of Decolation as my only DPS rune. I like to have some armor penetration from the beginning of the game.
Greater Seal of Defense, Greater Glyph of Shielding and Greater Quintessence of Fortitude is good to make Jarvan IV a solid tank, able to take lots of damage as soon as combined with the tank items listed above.

I run a standard 1/21/8 tank tree, taking all the good stuff from defense (maybe except nimbleness), improved exhaust (very optional choice, but i like that to make the enemies take even more damage, or if they try to escape) in the offense, and perseverence, good hands, awareness in utility (for leveling faster and having better health and mana regen. I would also recommend haste in utility, but again its totally up to you)

As you can see i only choose Tank/DPS items.
Start off with a Ruby Crystal, that you turn into a Heat of Gold right after getting Boots of Speed. Turn those boots into Mercury's Treads (good for tanking and good because of that CC-duration reduction). I would clearly recommend Mercury's Treads but you can choose to go for a different kind of Boots like Ninja Tabi for tanking, or maybe Berserker's Greaves if u want to go a bit more offensive. The next item is Frozen Mallet (love it because of the Attack damage, nice health and movement speed reduction on hit). Then grab a Sunfire cape (because it is both a tank item and a DPS item, which makes it perfect for a guy like Jarvan IV). Take Banshee's Veil next becuase of the spell block, magic resist, health and mana. As a super tank item go for Guardian Angel (remember u only live twice). And final turn Heart of Gold into a Randuin's Omen.

I start off by taking 1 point in each skill (first E then W then Q) and doesnt take more points in the Q skill until the end, because i only use it for his E-Q knock up combo.
From level 4-13 i shift between taking 1 point in E and 1 point in W (of course taking his ulti whenever i can)

Farming is very easy for Jarvan IV if you just take advantage of his passive ability for last-hitting minions, and maybe throw a Demacian Standard once in a while