As a none mana user, Boots of Lucidity are perfect for Riven. FROZEN MALLET IS YOUR MOST IMPORTANT ITEM. gives u some early health and durability, as well as keep them slow while u rape them some more. Also for Atma's Impaler and Hexdrinker, the order can be interchangeable based on the team you face. Wits End gives you more durability and obviously faster attacks. And finally, Bloodthirster allows you to tank down more tankier champs and still remain with high health.

Ki Burst IS YOUR MOST IMPORTANT SKILL, aside from ult. In late game it does massive damage and stuns them for a short moment while u rape them. When you engage into a team fight or any other fight i guess, start with ur ult, use ur E to dive in, W to stun, QQQ, for some decent damage, and use ur Ranged Ult to finish them off.

In my opinion, Ghost and Exhaust are the basic necessary Summoner Spell for non range AD Champions. Also with Ghost and Broken Wings, you can escape almost anything. Exhaust is self-explanatory.

Using E to dive into clumps of minions and following up with W will either kill them or leave them very low where u can just use Broken Wings to clear the rest up.