http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1739593326/202703050?tab=overview
I know... dick move playing her for the first time in a ranked game, but it went ok. Wanted some build advice from other Kalista players - what's your build order? I've read 20 guides and they pretty much all disagree on everything from Runes to Masteries to build.
Runaan + BT uses to be her to-go build in most matches. I haven't played a lot of Kalista myself but my duobot premade mains her and he always build her that way. It's also important not to go so ham early, as she haven't high dmg until some spears are stacked in her target (and for that you'll need attack speed first). Usually most meta carries like Graves or Sivir can trade back dealing more dmg than you, so be careful.
attack speed quints, ad marks, armor seals, magic resist glyphs
first item 
finish these after cutlass. tier 1 boots can come after vamp scepter.
The above 2 items give you a TON of survivability, mobility, and duel potential. The idea behind building her with attack speed and life steal is to use her mobility to put a lot of spears in the target, and then use your E (rend) to "smite" them as a finishing blow (or damn near close to it). The difficult part of kalista aside from mastering her passive is learning when to use your E.
third item (after botrk + boots) 
- more mobility, and AOE with your rend
fourth item 
- crazy survivability and some much needed AD (lifesteal stacks with your runaans)
fifth item 
- you're an ADC, so you need armor pen
sixth item 
- depending on the enemy team comp
