In the jungle, Jarvan has always been a low economy pick, which means a champions that can function despite being on low economy, or less gold than the opponent. As a support, he can still function around the same, but can change up his itemisation as he does not need to clear the jungle or be as tanky. The Jarvan pick should come in as a B4 B5 or R5 pick to round up a draft, mainly when his threats are not picked, and himself picked to specifically counter things like the Olaf and Udyr (and hecarim without his ultimate) due to their oppresive nature when ahead, but inability to get around walls without a flash. Jarvan's knockup combo and ultimate can reduce the oppresiveness of these kind of champions without a dash

Jarvan should try to poke his opponent in laning phase with his E, which should in most cases be levelled first. Against a heavy poke lane e.g. Caitlyn Lux, he can level W at level 2 for more sustain if he cannot get the level 2 power spike before the enemy. Otherwise, E and Q can allow an all in with ignite or exhaust should both sides be at level 2, or with jungle assistance. At level 6, jarvan can set up for ganks really well with his E Q combo and his ultimate, thus his opponents are likely to need to blow their flash even with a dash as there are 2 threats from Jarvan if they are not spacing correctly. Definitely call your jungler to camp your lane if you have freezes in your favour as Jarvan has alot of good gank setup just by his own.

Jarvan should usually opt for Moonstone Renewer as a first item due to it being such an oppressive item by consistently giving hp to Jarvan's teammates. Lucidity boots is a strong option and Jarvan should always opt for this choice unless plated steelcaps or mercury treads can find more value. Mobility boots or boots of swiftness only should be bought if Jarvan is losing lane badly due to early blunders, and the only value he can provide is spam ganking other lanes as he cant provide value in his lane anymore. Forbidden Idol items are always situational and one should never opt to "pre order" one which means one just perma buying an item just because he/she likes it. All forbidden idols items can provide good synergy with Moonstone Renewer due to forbidden idol increasing the base healing a champion provides, thus further increasing the effectiveness of Moonstone renewer. Arden Censer should be build if your team auto attacks alot, Staff of flowing water if your team has decent and above ap ratios, Mikael's against Crowd control besides suppression and redemption can find alot of value to negate as much value from huge AOE ultimates or abilities on the opponent team e.g Karthus or Miss Fortune Ultimate.

-Use E to help your jungler to leash his buff as it provides extra attack speed to your ADC, yourself and your jungler
-E can grant you assist to kills as it buffs your teammates' attack speed
-When Ornn rams into your wall, part of it is broken only
-Your Ultimate can block an enemy or teammate into a wall so be cautious of using it and do not block a teammate
-R can be recast to remove the wall
-Casting ultimate on a champion and E Q ing away can leave him in the ultimate while you can escape
-Dashes hard counter Jarvan so he should not be blind picked, unless used as a Support-Jungle 2 way flex
-Enchanters may feel oppressive to play against
-Remember you do not have to always go in and you should opt to peel for a carry if he or she is fed