This is my second guide, though I reluctantly never finished my Pantheon guide to begin with. This guide deals with Leona and how she plays; Any suggestions are welcome in the comments, appropriate changes will be made as seen fit.

This guide is still being worked on.

You want 4/24/1 masteries. The exhaust and ghost points can go a long away, and archmage's savvy will be useful. You want the armor, magic resistance, dodge chance, health, health regen, and tenacity from the defense tree.

The good:
Ghost - Good for escaping or chasing down an enemy.
Flash - Another incredibly useful summoner spell. Once more, can be used to chase down someone or escape. Very useful.
Ignite - A bit overused, but still useful spell.
Exhaust - Can stop someone from chasing you, or can halt them from escaping.

The bad:
Heal - Useless if you play carefully and properly.
Revive - Who uses this?
Smite - Not junglin'.
Teleport - Though useful for getting around the battlefield, it's bland otherwise.
Cleanse - Not really worth it, but Leona is a tank after all.
Fortify - Near useless.
Clarity - Conserve your mana and you won't need this.
Rally - Near useless.
Clairvoyance - A much better spell can be chosen than this.