Abzan Aggro (Standard)

Sideboard guide:

UB Control: Apply as much pressure as possible; don't get distracted by Ashiok - that's what Downfall is for. Valorous Stance can be a nice surprise, but it unfortunately doesn't protect vs Silence, Vault, or Bile Blight (unless the Blight is combined with combat damage).
In: All copies of Boon Satyr, Mistcutter Hydra, Hero's Downfall, Ajani (Mentor), Thoughtseize,
Out: All copies of Bile Blight, 1 Land (Caves?), 2 Abzan Charms. Try to avoid removing threats; if you have to, drop a Roc

UW Control: Drop small threats when they have mana up and big threats when they're tapped out (or when you can TS first)
In: All walkers. All copies of Mistcutter Hydra, Boon Satyr, Hero's Downfall, and Thoughtseize. 1-2 copies of Glare
Out: All copies of Bile Blight and Heir of the Wilds. Down to 2 Abzan Charm, 2 Anafenza, 2 Wm Roc.

UWR Control: I still don't know how to navigate this match-up. Rushing out threats that we can't protect is bad, because they run Lightning Strike and Anger. Wait until you can drop threats and protect them, even if that means that they might get countered, because this deck doesn't run as many hard counters (6? It also runs Mindswipe) as UB or UW Control. If you can establish a board presence and protect it, then you should be in the clear. Anafenza is a good turn 3 drop, but drawing cards with Abzan Charm works, too.
In: Ajani. All copies of Mistcutter Hydra (X=4+), Glare of Heresy (for Elspeth), Thoughtseize.
Out: All copies of Bile Blight, Heir of the Wilds. Drop 1 Fleecemane and 1 Abzan Charm.
Dromoka and Reaper would be decent in this matchup, since they're too big to die to standard burn. It would also be nice to have something, like Erase, Deicide, or Unravel, that can deal with an inactive Keranos.

Abzan Midrange: Tune the list, go a bit bigger
In: All walkers (except maybe Nissa), All copies of Glare of Heresy, One copy of Back to Nature, All copies of Downfall
Out: All copies of Bile Blight; Down to 2 copies of Thoughtseize, 3 copies of Anafenza

Abzan Aggro - Tune, go a bit bigger, run more threats
In: Every copy of Glare of Heresy and Downfall; all walkers except Liliana
Out: Down to 2 copies of Bile Blight. Drop all copies of Thoughtseize. Down to 0x Utter End

Abzan Whip - More threats, keep BB in case of Hornet Queen
In: All copies of Back to Nature, Sorin, Elspeth, Anafenza, Valorous Stance
Out: Thoughtseize

UW Heroic - Go big or go home
In: Glare of Heresy, Elspeth, Back to Nature and other instant speed enchantment hate (other than Utter End), Downfall, Sorin, Valorous Stance, Thoughtseize, Ajani, Murderous Cut
Out: All copies of Bile Blight, Utter End, 1 or 2 Anafenzas

Red Aggro - trade until you're able to pull off a drown
In: Drown, Bile Blight, Sorin, maybe Downfall
Out: Thoughtseize, down to 2 Abzan Charm, any walker other than Sorin, Utter End

Jeskai Tokens
In: 3x Drown, up to 4 Bile Blight, 1 Glare, enchantment hate
Out: Down to 3 Anafenza, drop all copies of Heir of the Wilds, Valorous Stance, and Abzan Charm

Mardu Tokens
In: 3x Drown, 1x Back to Nature (to get multiple copies of Chained to the Rocks), all copies of Bile Blight, Murderous Cut, Downfall, Sorin
Out: Utter End, down to 2 Thoughtseize, drop all copies of Heir, most or all copies of Abzan Charm, Valorous Stance

Mardu Aggro
In: 2x Drown, Downfall, Cut, Sorin, Bile Blight
Out: Thoughtseize

Mardu Midrange
In: Downfall, Cut (if expecting SBD), 1x Back to Nature, Elspeth (use as removal), Glare (for Elspeth/Brimaz)
Out: Valorous Stance (hits Butcher&Brimaz and nothing else), down to at most 2 BBlight, possibly fewer depending on what you expect, A. Charm is only good vs Sarkhan (maybe run 2); drop to 3 Anafenzas

Red/White Tokens
In: 3x Drown, 1x Back to Nature (to get multiple copies of Chained to the Rocks), all copies of Bile Blight, Murderous Cut, Downfall, Sorin
Out: Utter End, down to 1 Thoughtseize, drop all copies of Heir, most or all copies of Abzan Charm

Green Devotion - this is our worst match-up. Try to control them and slow them down. If this match-up is prevalent, the Boon Satyrs in the board should be replaced with board wipes, most likely EH
In: All copies of Sorin, Elspeth, Downfall, Cut, and Thoughtseize; 1x Drown, 1x Back to Nature if they run enough enchantments, up to 3x Bile Blight, Valorous Stance
Out: down to 2x Anafenza, 2x Rakshasa, 2x Wm Roc, Utter End
Alternatively, on the play, try to race them:
In: Sorin, all copies of Bile Blight, 1x Back to Nature, 1x Valorous Stance
Out: Thoughtseize, Utter End

Possible changes:

Warden of the First Tree:
I don't think he fits well into the main deck, but I could see running it in the sideboard as a way to add cheap threats vs Control decks. Maybe he could be a replacement for the Heirs?

Reaper of the Wilds may be a good fit as a 2-of; she beats Rhino and can avoid removal better than Rakshasa.

Herald of Torment could be a 1-of in the 75, since dropping him on a Siege Rhino can end the game, but it still dies to Vault and EH when it's bestowed, so it'll depend on how common those particular cards end up being. If Crux is way more popular, he should definitely be added back in (due to living through it if he's bestowed).