Abjuration (15 feats)
The school of defense and magic negation.
General: Combat Expertise, Dodge, Toughness, Great Fortitude, Lightning Reflexes, Iron Will, Skill Focus (Acrobatics) – used to avoid AoO
Casters: Arcane Shield (Arcane CL 10), Combat Casting, Destructive Dispel (cast dispel magic, CL 11), Dispel Synergy (Spellcraft 5), Improved Counterspell, Spell Focus (Abjuration)
Martial: Bolstered Resilience (DR), Shield Focus (+1 BAB), Saving Shield
Worst case scenario, +2 to a saving throw.
Conjuration (14 feats)
The school of extraplanar entities, matter creation (crafting), teleportation, and healing.
General: Gunsmithing, Master Alchemist (alchemy 5 ranks), Godless Healing (Inner Sea World Guide), Fast Healer (ignore Endurance/Diehard pre-reqs – this is not a great feat), Demon Hunter (Kn Planes 6 ranks, Inner Sea World Guide), Skill Focus (Kn Planes or Heal)
Casters: Spell Penetration, Spell Focus (Conjuration), Item Creation feats?
Martial: Master Craftsman (craft 5 ranks)
Special: Alignment Channel (channel energy), Dimensional Agility (use dimension door), Elemental Channel (channel energy), Evolved Companion (Cha 13, animal companion), Evolved Familiar (Int 13, Cha 13, familiar), Improved Familiar
This one's actually quite challenging. It includes a lot of different things – none of which is associated with many solid pre-requisite free feats. Spell Penetration isn't bad, and outsiders are a common source of SR so it kinda fits. If you include Item Creation feats then casters get some options, on top of some neat stuff for casters with pets. Martials are harder – the DR penetrating feats that would be thematically similar to Spell Penetration all have elaborate pre-requisites. Teamwork feats would be potentially thematic with the “summoning allies” thing but unless a character has tactician, solo tactics, or similar they would need someone else to spend a feat to actually enjoy the benefit.
Note: if you give out Master Craftsman I highly suggest houseruling it to act as Craft Wondrous Item or Craft Magic Arms & Armour using the selected skill, which would make it an actually modestly useful feat. As is it just enables a non-casting character to take a crafting feat later.
Divination (9 feats)
The school of information and preternatural reaction speed.
General: Improved Initiative, Alertness, Amateur Investigator (Int 13, rank in a knowledge skill), Skill Focus (Knowledge, Linguistics), Lightning Reflexes
Caster: Detect Expertise (Int 13, can cast a detect spell), Spell Focus (Divination)
Martial: Blind-Fight, Combat Reflexes, Shadow Strike (BAB +1)
There aren't a lot of feats in this category, but there are several good and broadly useful ones, with Improved Initiative being the biggie.
Enchantment (12 feats)
The school of social manipulation and morale.
General: Antagonize, Battle Cry (Cha 15 and BAB +5 or Perform 5 ranks), Flagbearer (Cha 15), Persuasive, Taunt (small size), Voice of the Sibyl (Cha 15), Steadfast Personality, Iron Will, Skill Focus (bluff, diplomacy, intimidate, sense motive, perform)
Caster: Encouraging Spell (Cha 13, Diplomacy 6 ranks, Magic Tactics Toolbox), Spell Focus (Enchantment)
Martial: Enforcer (Intimidate 1 rank), Intimidating Prowess, Performance Weapon Mastery
Not a ton of variety in here, but if you make sure the title is a strong hint as to its contents no one should be disappointed. Worst case scenario someone picks up Iron Will to resist enchantments better.
Evocation (13 feats)
The blasting school, associated with primal energies, force, and damage.
General: Skill Focus (Intimidate)
Caster: Arcane Blast (arcane CL 10), Arcane Strike, Elemental Focus, Spell Focus (Evocation), Elemental Spell, Intensified Spell
Martial: Deadly Aim (Dex 13, BAB +1), Point Blank Shot, Power Attack (Str 13, BAB +1), Quick Draw (BAB +1), Improved Critical (BAB +8), Improved Natural Attack
Unfortunately martials will probably have picked up the most obvious choices (eg Point Blank Shot, Power Attack) because they are the fundamentals of basic combat styles. Quick Draw and Improved Critical will hopefully offer something, but more ideas would be good. Loosening up your no feat pre-reqs guideline a bit could allow you to include things like Improved Bull Rush, Improved Sunder, or Double Slice. Noncombat clerics, oracles, and witches might also not have the best time with this list because they don't have as many blasty or elemental spells as wizards and druids.
Illusion (10 feats)
The school of deception and stealth.
General: Deceitful, Iron Will, Conceal Scent (stealth 1 rank, survival 1 rank, Osirion Land of the Pharaohs), Skill Focus (bluff, disguise, stealth)
Caster: Spell Bluff (Bluff 5 ranks, Spellcraft 5 ranks), Still Spell, Silent Spell, Spell Focus (Illusion)
Martial: Shadow Strike (BAB +1), Dirty Fighting (Dirty Tactics Toolbox)
Not really sure what to do with this one – there don't seem to be a lot of good feats for this theme. I've included Iron Will and Shadow Strike as anti-illusion options but it's still not a great list. Feinting would be appropriate on the martial side, but those feats have pre-requisites.
Necromancy (15 feats)
The school of undead (bolstering, controlling or damaging), life force, afflictions and fatigue.
General: Necromantic Affinity (Con 15, Inner Sea World Guide), Endurance, Great Fortitude, Skill Focus (Heal, Kn Religion)
Caster: Ectoplasmic Spell, Merciful Spell, Sickening Spell, Poison Focus (Alchemy 1 rank, Alchemy Manual), Spell Focus (Necromancy)
Martial: Critical Focus (BAB +9), Deadly Finish (BAB +11), Improved Critical (BAB +8), Vital Strike (BAB +6), Treacherous Toxin (BAB +5, sneak attack, Dirty Tactics Toolbox)
Special: Command Undead (channel negative energy), Improved Channel (channel energy), Life Lure (channel positive energy), Turn Undead (channel positive energy)
My biggest concern here is that the thematic martial feats all have significant BAB requirements.
Transmutation (15 feats)
The school of shapeshifting, physical enhancement, and mobility.
General: Acrobatic, Aspect of the Beast (senses, claws, or leap, ignore wild shape pre-requisite), Athletic, Deepsight (Darkvision 60ft), Endurance, Fleet, Great Fortitude, Lightning Reflexes, Toughness, Sharp Senses (keen senses trait), Skill Focus (acrobatics, climb, swim, escape artist, fly)
Caster: Arcane Strike, Shapeshifter Foil (arcana or nature 5 ranks, can use polymorph), Spell Focus (Transmutation)
Martial: Improved Natural Attack, Improved Natural Armour (Con 13, natural armour, Bestiary)
I'd like to include one or two more martial options here, but I think it's still a reasonably good list.