I find this champion takes a bit of practice, but once you get used to the skill sequence, it becomes a lot easier to take advantage of an early game lead.

Note the above screenshot was prebuff. This is a game with Riven after the buff using this build:

Huge difference. Her playstyle has improved tremendously. She is now the AD carry that she was meant to be.

Some people are saying there is not enough AD in this build. To them I say...start your Frozen Mallet earlier by getting a phage. But really, you are getting a lot of AD from this build, and it's relatively cheap. If you get too much gold at the endgame, now that Riven's endgame has improved with the buffs, you should replace Youmuu's Ghostblade with a Trinity Force / Warmog's Armor or Wriggle's Lantern with a Madred's Bloodrazor. Either one will work well if you are really fed, like I ended up being in this game above.

Riven's early game harass is very powerful, so use that to your advantage to get a few easy kills in the beginning of the game.

Start with a Doran's Blade. Then, depending on the opposition, you will either want the Ionian Boots of Lucidity or the Mercury's Treads. I would go with Mercury's Treads only if the other team is caster heavy, otherwise, CDR is a good stat to have since she relies on her cooldowns to deal damage.

You will notice that most of the items have either armor or magic resist. Build accordingly, ie do not get armor if they do not have any melee or AD champs, and conversely do not get MR if they do not have any casters or AP champs.

If you are lucky, this means you can dodge all the items with armor or MR to opt for some more damage with something like Infinity Edge.

After your core build is complete, finish off with a Frozen Mallet and an Atma's Impaler so don't get nuked late game in a team fight. Last Whisper is not a bad item to get at this point if your opposition is armor heavy.

Don't forget to use your Wriggle's Lantern in bushes so you don't get ganked and you help your team.

Yes, I realize I am just taking a bunch of items from the recommended items list, and it might be crazy, but recommended items actually work pretty well with Riven.

The skills are very simple. You want an early point in Broken Wings for that early game harass. This will help you pick up kills very easily at low levels.

Next you get a point in Ki Burst. At level 2, start using Ki Burst interwoven with your Broken Wings combo.

At level 3, pick up Valor for its utility. This can be used as an extra dash to close the gap between enemies, as well as an escape for when you are done dealing damage. Mastering this ability is key, for although it deals no damage, it does block a LOT of incoming damage and gets you in and out of fights safely. It also reduces its cooldown with each point so you want to max this out second.

The reason you max out Ki Burst first is because it does a MASSIVE amount of AOE damage and scales really well with AD. Therefore, the E->W combo will be your best friend.

Do not open with Broken Wings, because this will get you killed. It is the common mistake that a lot of noob Riven players make. It leaves you completely open to attacks, and does not deal a lot of damage to the enemy.

Open with Valor into a Ki Burst for that burst of damage. Remember, only use Broken Wings if you need to close the gap for a Ki Burst to land. Your main goal is to land a Ki Burst on as many enemy champs because this is your main nuking ability.

The sooner you max out Ki Burst, the lower the cooldown will be and the higher the damage output will be, so make sure you get that first.

And last but not least, NEVER OPEN WITH Wind Slash. I see a lot of noob riven players who activate their ultimate before a team fight, and open with a Wind Slash. Don't be that noob. You save that for the very last second, when enemies are about to die. It is a cone nuke that does more damage if the enemy is low on health, kind of like Garen's ultimate. You wouldn't open with Garen's ult, so don't open with Wind Slash. Make sure your ultimate is activated before engaging in a team fight, and if you have Youmuu's Ghostblade, then activate that too with your ultimate. It will make for getting kills a lot easier, and you will see enemies drop faster than a hydrogen proton traveling around the Large Hadron Collider. No one got that? hmm...

Riven can be a great feeder if you do not get armor and magic resist. That explains the runes as well as the masteries. She is a DPS fighter, a melee chamption, and not very durable. In order to get in and out of fights safely and deal tons of damage, make sure you have some survivability.

It will ensure you live till the end of a team fight, and using Wind Slash at this point is a gamechanger. You can make or break a team fight if you use your Wind Slash at the end. You can never use Valor enough. Whenever it's up, use it. Just because it does no damage, do not neglect it, because it will save your ***. The added mobility is a plus. Use it to get to lanes faster, or run to enemies faster, even when you are far away on the map. There is no mana cost, so just spamming your abilities every cooldown is not going to hurt you if your target is far away and you know there are no other enemies around.

People don't use their abilities enough. Lower that cooldown and spam your Valor because it is one of the most useful spells that she has. Getting blue buff for the cooldown reduction is not a bad idea as well. Always Valor before you Ki Burst and you will be dropping them like flies in no time. Use Broken Wings only to chase while dealing damage, or to run away after a Ki Burst when they aren't low enough and a Broken Wings combo will not kill them.

It's all about getting used to using your abilities to not only deal damage, but move and jook the enemy as well. Using your ultimate will deal a ton of damage while increasing the range of your abilities so don't forget to use your ultimate a lot. It's on a short cooldown (relatively) so why not just activate it every time it's up. You will get a lot more kills this way if you just use your ultimate, even when you don't think you will need it.