Welcome to my build/guide. completely reworked to fit riven after the recent nerfs/buffs.

I prefer to max Ki Burst first since the AD ratio is 1:1 and the stun is awesome.
Valor is up second since that little step and shield is well worth those points, dodging skillshots like Ashe's Arrow, Nidalee's Spear or whatever else it be, awesome spell.
Broken Wings is maxed last since it won't have a reduced cooldown if leveled up.
Blade of the Exile of course up this ability whenever you can.

The DMG output of Broken Wings in the Early lvls combined with your passive really hurts someone and due to the lack of movespeed in the beginning it's close to impossible for the enemy to dodge your hits. As soon as you hit lvl 3, smack the enemy with Broken Wings into Ki Burst and then Valor to either chase and get an Autohit off or Valor away from them to prevent counter harassing.

As soon as Ki Burst is maxed you can hurt someone sooo bad with that combination, especially with some strong AD/AP mate on your lane this is gonna hurt even more :)

For the ones who still don't know how to deal dmg with her:
Jump into them with your Broken Wings combo, Ki Burst them (yes, ki burst is your highest dmg skill) and then Valor out. Try to get those 3 passive charged autohits off, this really hurts.

Completely Reworked: Long Sword and a HP pot for some sustain and damage.
Get Mercury Treads as soon as possible since they make you quite tanky in lane, the mobility is a must, if you feel like you dont need them, get Boots of Swiftness.
The Brutalizer is the bridge to your Ghostblade and really boosts your early to mid game power.
Last Whisper is picked immediately afterwards for the same reasons.
Youmuu's Ghostblade is built from our The Brutalizer.
Core build completed.
Trinity Force compliments riven well, except for the mana, still this item works great on her, haters gonna hate.
Wit's End new fav item somehow, cheap item with great benefits.
Frozen Mallet some HP + Slow and flat AD, can be replaced with any item you like.

Flash and Exhaust tagging the highest damage enemy in a Teamfight with Exhaust might win it for you ;)
SECOND BUILD:
Flash and Cleanse since we don't pick QSS with this build, but FoN :)

Using Broken Wings in tandem with Ki Burst could clear out some weakened Minions for you, but you might rather choose to stick around the creeps and Last hit the normal way.

Another way would just be to autohit all 3 ranged minions ~ 2 times and then Ki Burst(ONLY IF MAXED instead it will just push them a bit closer to being a possible last hit)

Riven might as well just CC the enemy for a strong ad/ap carry thats on lane with you, Ki Burst in combination with Brand's Pillar of Flame turns to a great harass too.

And always remember that the third hit of Broken Wings is CC too that could keep a chasing enemy off for a second so your Teammate is able to Escape. Your best bet would be to use Broken Wings 2 times, then Ki Burst and Valor through the enemy to smack them further into your team/teammate with the third hit of Broken Wings

In a Teamfight try to Surprise them by jumping right into them with Broken Wings and Valor into an immediate Ki Burst your team may clean up the mess then, kill runners off with your Blade of the Exile and Wind Slash.

You may aswell want to Activate your Ult right before running into the Enemy team for Extra damage on Ki Burst and Broken Wings aswell as the shield from Valor

Reworked for great damaging potential.

Runes:
Greater Mark of Desolation Obviously best Reds for any Physical champ.
Greater Seal of Attack Damage/ Greater Seal of Armor if you like Early game power pick the AD if you'd rather be able to take a little more punishment pick the Armor.
Greater Glyph of Attack Damage/ Greater Glyph of Magic Resist same: if you love Early game Bam, pick AD if not pick the Mresist.
Greater Quintessence of Attack Damage Good for you, even more bling to your Bam.
but here some other Quints that are viable as well:
Greater Quintessence of Health
Greater Quintessence of Desolation
Greater Quintessence of Armor mixed up with Greater Quintessence of Magic Resist

If he is chasing you try to set something up for a kill if your teammate is somewhere nearby if not keep running, if your teammate is being chased tell him to run through a bush where you stand in and set it up for a kill.
If there are many other enemies MIA or somewhere close by, try to Ki Burst into Valor to stun and get away from the now stunned champion.
You could also run into a bush, wait for someone whos chasing to enter, and then Ki Burst + Valor away from them.

When fighting skillshot based champs like Ezreal you will always want to abuse your Mobility to your advantage :) Valor through them or dodge Skillshots with it, dance around them with Broken Wings to avoid being hit and stuff like that.

Ki Burst is the skill i like most from Riven, stop Kata ult with it, or Karthus, or Ezreal, or Wukong, or Malz, Lolwick, etc etc etc.

and thats about it, hope this helps you out and you can tell those pesky QQers: Cry me a Riven.

Peace'd out.