I know my last report has drawn the attention of many of you wanting to improve your skills playing Faeries in Modern, but some sideboard tips would've been useful. So let's share some of my post-board plans with you. Sideboarding with Faeries is sometimes counterintuitive, but once you realize what your game plan is, you'll find out some cards you considered good actually don't help you at it.
Usual tip: when on the draw, you may take out the 26th land, specially when playing against non-control decks.
+1 Thoughtseize, +2 Engineered Explosives, +2 Grafdigger's Cage, +2 Glen Elendra Archmage
-4 removal, -1 Sword, -1 Bitterblossom, -1 Cryptic Command, -some beaters
You cover all their game plans and take out some inefficient spells. Cage isn't the best answer (it shuts down Caster and Archmage's persist), so you may try without them. You don't need Blossom too early, so consider it a cuttable beater. MClique on the upkeep isn't a timewalk if they have Electromancer in play (actually it's suicide).
It depends a lot on their plan for post-board games. If they're playing the All-In version, bringing in Spellskite, Smother and Thoughtseize is interesting. The UR Tempo Twin would require Disfigure and Batterskull. The RUG version can be fought just with Smother. Cryptic Command is the first suspect to go out, and will be definitely cut if we're smelling Blood Moon. Cliques are worse against decks that can play their threats with flash, so you may cut some of them, specially if we're replacing them with Archmages.
+2 Disfigure, +2 Smother, +1 Damnation, +1 Batterskull, +1/2 Engineered Explosives
-1 Go for the Throat, -2 Thoughtseize, -3 Cryptic Command, -1 Mistbind Clique, -1 personal choice
Affinity has two plans: swarm and doped guy ftw. Blossom shuts down the later, bring in removal to stop the former. IoK does wonders at stopping it on the play, but you'll be at least one game on the draw.
Against Living End
+1 Thoughtseize, +2 Glen Elendra Archmage, +1 Damnation
-2 Spell Snare, -1 Sword, -1 Vendilion Clique
Make sure you don't leave any Spell Snare against them and the Cages are left in the sideboard. Play tightly, always around Violent Outburst or Beast Within out of nowhere, so Vendilion Clique will be harder to cast. Don't board out the 26th land on the draw.
+2 Glen Elendra Archmage, +1 Thoughtseize, +2 Spellskite
-2 Dismember, -1 Sword, -1 IoK, -1 MClique
The version with Commands is a tough match-up. If I'm playing Glen Elendra Archmage in the sideboard is because of that pairing. If Scapeshift is a popular deck in your metagame, play Tectonic Edge instead of Ghost Quarter. You may push them early, although countering some ramp spells will slow them down. Once they've gathered 7 lands, they can go off, so you'll need resolved Archmage, or Cryptic Command with some back-up in hand. Beware of Teferi...
Seeing those match-ups, Nihil Spellbomb would've been more useful than the Cage, but Pod is still a popular deck. You also must evaluate Cryptic Command correctly. Against mid-range decks is a brutal card, but against fast aggro or combo it's too slow or expensive, and against other blue decks it isn't the most efficient spell as well.