hellur mobafire. Atherton Wing here, with a guide on Leona, prepare to tank.

Build 1 - Balanced Trinity tank
The Veteran
This build emphasizes anti-carrying. It's hella expensive, so you should be soloing top, preferably 1v1, focusing on cs and staying alive. Once you farm your Trinity Force, you gonna be dealin hella damage and be almost unkillable. Find your way to the back of fights, and assassinate their carries, disrupting the enemies flow. Personal favorite right here.


Build 2 - Balanced Full tank
The Vanguard
This build is a lot less expensive and slightly more tanky, focused on initiation and soaking damage. Its more noob friendly, so if you're just picking her up I suggest this build. Dive headfirst into the enemy team, disabling as you go, as this build lets you pull of stupid good teamfights.

Build 3 - Balanced Support tank
The Momabear
To take full advantage of her passive, support AD carry duo lane. The playstyle is similar to taric, seizing bush control. You wont be nearly as tanky with this build, which focuses on CDR and health, but with a team to back you up, you can pull of some amazing stunts, and still have a solo lane farmed ad carry bot. Remember to ward!

The Veteran/The Vanguard
This rune-set is geared towards a strong tanky early game, where Leona is weakest.



Flat armor helps you survive minion aggro and early harass in lane
other alternatives are flat magic resist, or magic penetration (if its all you have)
Dodge is an extremely useful and difficult to come by stat, runes are the best place to pick it up. late game, six/seven percent is a VERY LARGE AMOUNT of damage reduction to have, when autoattacks can hit for up to 300/400
alternatively you could pick up flat armor, or perhaps health per level.
Flat magic resist to help you survive the laning phase versus caster types.
alternatively magic resist per level, or CDR, but flat is best because Leona's weakest phase is in lane.
HEALTH ES #1 FOR LANING PHASE. be tankier.
alternatives could be flat armor or magic resist, or health regen.




The Momabear
This rune-set is geared towards a duo lane mentality, where you aren't taking as much damage, instead specing for a more ability based approach.



Flat Magic resist for those pesky taric/brand lanes, and whatever other magic damage you may come across.
Flat Armor for tanking those towers and auto attacks at level 4 when your xin ganks your lane.
CDR per level for spamming of skills late game, indirectly making you tankier because of your W.
Flat health like a baws.

any of the alternatives also may be used for the support build.

The Veteran
0/13/17
This setup gives you a nice balance of defense and utility, bringing that flash/tp cooldown down is a big bonus.
taking teleport allows you to recall for items and be back in lane instantly, making your presence huge, and later it allows you to join teamfights from across the map if you made a mistake, or backdoor.
flash is OP and lets you make plays and escape.

The Vanguard
12/9/9
12 in offense gives you a little bit of survivability in top lane, simply because if you do NO damage then no matter how much you tank you cant solo.
Teleport for lane dominance and joining team fights, exhaust for better dueling and added utility.


The Momabear
0/9/21
Standard caster/support setup, picking up the improved clairvoyance is key to being supportive, while that extra armor and magic resist in the defensive tree helps you tank away.
Flash is still OP.

The Veteran

Shurelya's Battlesong gives you some early staying power in lane, and will help your team with positioning into late game with the mini ghost. Leona benefits from every stat Trinity Force gives, and both on hit effects. The slow just makes people cry, and the extra damage is the base of your offtanking. Here things get a little tricky. depending on who is fed, you either pick up a Wit's End, or an Atma's Impaler, finishing the other after Warmog's Armor. wits end is an undervalued tank item, 42 bonus damage and 50 magic resist is nothing to scoff at. Atma's makes your autoattacks hit HARD on teh carries making them weep as you crit for 300 damage. Selling Shureliya's late game for Aegis of the Legion is a good choice, because you benefit less from the regen it provides, and although the active is nice, it's made up for with the tankyness aura of Aegis. this is assuming that your support hasn't picked it up. if he has, stick with Shurelya's.
of course if you actually manage to finish the build to that point though, you probably aren't doing something right. xD


The Vanguard

The build starts the same as the veteran, but quickly changes direction when instead of heading for Trinity Force you pick up a Heart of Gold and an Aegis. Shurelya's AND Aegis? Wait you must be joking. Think of the teamfight presence. Just imagine it. And then you add a Randuin's Omen? the enemy is crying OP by now as you slow them, haste and tankify your team. Force of Nature rounds up your magic resist to a more pleasurable level, and at this point its really your choice what you go for. You can save a spot free for wards, get a Frozen Mallet for health and chasing power, Banshee's Veil for added cc soaking, the possibilities are limitless. i list a Warmog's Armor because that's what will give you the most effective health, but it really is situational.


The Momabear

Picking up philosopher's stone and Heart of Gold gives you your alternative cash flow, and picking up Aegis of the Legion helps your survivability. Glacial Shroud makes you a bit tankier, and is the first of your CDR items. Soul Shroud gives your team an aura that ****ing owns, and Frozen Heart and Abyssal Mask are even more auras. this build almost caps your CDR, giving you plenty of leeway to spam your ult, and other disables, making life hell for the enemy. and always remember, it is more important to have at least 2 sight ward than your next item. don't cs, that's your carry's job. This build is malleable, use common sense and build what your team needs. heavy caster allies? abyssal. enemy carry raping your team? frozen. be creative.

Leona comes with a lot of tankyness, and her base damage on her skills is pretty damn high. her burst is deceivingly large, use it to your advantage.


TL:DR
if you're looking for the most effective build, go with the first.
easiest to pick up, second
duo laning, third.