This is a basic guide to riven with recommendations based on experiences I have had while playing. This is NOT a carry guide, but rather a perfect pusher guide for clearing into the base, which is based on laning in summoners rift, with some jungling after level 4 or the first revolver.

The AOE and healing from spell vamp means that if you can hit 2-3 enemies with a single ability, you will gain a significant amount of life as your plow through a lane. The CD reduction means you can near-consistently keep the life feed going. For taking towers, Riven's best bet is to keep destroying waves coming behind the tower, and duck out as soon as the opposing team comes to gank you.

NOTE: The bonus damage from riven's innate DOES NOT affect towers. Save your abilities for the waves.

Rune Build
Riven works well with a strong hit, and early movement boosts are essential. The low starting health begs for the extra from runes, though if you prefer dodge might be more your style.

Alternately, you can focus armor penetration over the damage to avoid mid to late game damage nerf on tanks. This makes it more difficult to time minion kills early on, but gives you better endgame focus.

Mastery Build
This build focuses on speeding up your abilities so you never stop moving, in or out. As much CD reduction as you can get lets you walk through minions, teamfights, and jungle as well once you start getting spell vamp.

A lot of people prefer the extra damage to compensate from 21 offense, but in reality the CD reductions will empower your early game more than the 4% damage boost.

Item Build

Getting the brutalizer early gives you some mid game damage, but you should focus on pushing lanes until you can build the gunblade and revolver - 40% spell vamp means in a lot of situations you can refill you meager life pool completely by racing through minions. I find that sheen is useful if you can fit it, replacing doran's blade at the end if you build all the rest. Tiamat is preferable to sheen for pushing - for taking down champs, sheen is better (and trin force even better yet)

If you want to, you can jungle to allow your laning partner to get more exp every time you complete a gank or dual gank. This gives you both more exp and gold and helps you win.

The best way to up your minion wave damage is to focus on your 'W' ability Ki Burst, because its cooldown scales as it levels. Later, when you will be in more team fights, 'Q' broken wings needs the damage boost to be more powerful. The focus on spell vamp plus your AOEs refills your life, and if you can get to these without feeding too much you should be able to refill as you go, becoming less dependent on the shield dash, which is best for getting out of hairy situations, or to get ahead of a fleeing foes and take advantage of one more strike with your ability boosted damage.

If you don;t like the survivability or have a bad connection, 'Q' Ki burst + 'E' Valor will let you run up, burst minions, and dash away without worrying as much about ebing harrased. since the shield scales with AD, it gets stronger as you level and buy items, meaning it keeps potency, but its base rises fast enough in early game to compensate for a lack of items if you prefer it over the Broken Wings damage. Again, modify to fit your play style.

I personally prefer exhaust and ignite for early game. If you think it prudent to be more mobile, skip ignite and go with teleport to get to where u need to be, or flash as a bonus escape. Honestly, riven will rarely be lacking some button to push between the rapid cooldowns and the items (Gunblade, ghost blade) that you can weave in to your attack combos. the gunblade does trigger spell vamp, meaning it help your deceptively fast regaining, but never initiate with this build, it help to finish a teamfight, not engage directly.

If you are less agressive, Ghost and Flash are excellent to enable getaway, since it is EASY to overextend with the great surges Riven has.

As with all characters, riven is best practiced the first few games against bots to learn the timing, preferable the easy bots then the intermediate, before you try and face real opponents. Your weakness will always be stuns and interrupts, so avoid trying to gank the champions that seem to enjoy focusing you with those. Do not initiate team fights. Jump in after the tank initiates and throw in a lot of damage expecting assists - hunting kills with this build is pointless, focusing on groups maximizes your damage, especially after you get Tiamat.

Riven is a great champ and a lot of fun to play. this was my first guide and first RP bought champ - totally worth it.