This isn't intended to be your regular "this is how you do it" build, you can follow it exactly and you will most likely do very well but it's intended to provided a foundation for people to experiment a little. I'd love to hear comments from people saying "I did X or I changed Y." I don't claim to be some sort of pro with all the answers on Oriana, I love people taking my build one step further.
**Please try it and don't just look at smite and think to yourself -Fail- and vote this build down.
Runes are pretty self explanatory, they are designed to add to your flat AP for early game last hitting (and maybe ganking) and magic pen, which has utility throughout all stages of the match.
Ignite should be pretty self explanatory but smite is where I get the odd looks every now and agian. It seems to have a bad rep but I pick smite on most characters nowadays. It will be needed for a great many aspects in this guide and never stops being useful. It allows you to do numerous things like take blue/red easier, possibly steal them, and last hit as well which provides much needed gold.
This is the area where you can experiment a little. I just prefer the offense tree and still snagging the experience mastery from the Utility tree. As mentioned before, Experiment with it! Let me know what works for you.
I've found there are two ways to do the skill sequence for Oriana and it all comes down to if you want to deal damage or be a support.
I choose the sequence above because I prefer to solo the top and find that the extra damage that comes from your ball Attack is a great way to get the last kill on minions and to harass.
First off, you will want to change your masteries to utility or defense maybe.
For the talent sequence just reverse the order and get Command: Protect before Command: Attack.
My Oriana Playstyle / Tips
Oriana is very squishy until you reach mid-game. Try to hide behind your minions and harass with your ball attack as much as you see fit.
*Keep in mind you have no "Get the hell out fast" spells so try to avoid direct confrontation until mid to end game.
Once you have your Command: Protect spell, try seeing if you can throw your ball just past an enemy champion, and then recalling it quickly after for a double attack.
Try saving smite for the enemy cannon minions, any extra gold you can get will help.
Try waiting for as long as you can before you drop the Kage's Lucky Pick.
If an enemy is playing you close to a tower, use your ult to flip him across your ball into its range of fire, it will be tricky but it has worked for me in the past.