One of the things I loved about later editions of the game is the ideas of templates. It allowed you to come up with all sorts of strange and interesting ways to alter a monster without needing to create something from whole cloth. I’ve mulled the idea over and come up with a quick way to modify existing monsters to make them a bit more special and potentially dangerous without having to create new ones each time.
For ACKS, a lesser template adds one * worth of XP to the monster’s value. A greater template adds two * to the monster’s value. Alternatively, a template of either value simply adds one * if you prefer less variety or prefer to keep xp low.
Lesser Templates
Aggressive-The monster gets a +2 to hit and damage on all of its attacks.
Tough-The monsters gets +2 HP per HD, and +1 to all saves.
Fast-The monster’s AC increases by 2 and they gain a +2 with ranged attacks and initiative. Movement is increased by 30’
Supernatural-The monster needs magic weapons to hit, can see invisibile, but cannot touch something protected by Protection versus Evil unless attacked first.
Greater Templates
Brutal-The monster gets +4 to hit and damage on all of its attacks.
Unyielding-The monster gets +4 HP per HD, and +2 to all saves.
Fleet-The monster’s AC, ranged attacks, and initiative increase by +4. Movement is increased by 60’
Occult-The monster can cast 1 spell per 2 hit dice, with a maxiumum level of ½ their HD, as innate abilities. Round up.
In play example:
The Ogre Village of Black Heart is led by a direly potent Ogre Chief. Known as an aggressive brute, his service to dark gods has given him occult power. Many have tried to kill him, but he is too tough to die.
This would break down as an Ogre Chief with the following stats:
Mv 90’, AC 7, HD: 8+18, HP: 61, +2 to hit and does 2d6+3 damage, SV F8 +1, XP: 2600. He can cast 4 spells a day, of up to 4th level. The Judge picks Dispel Magic, Lightning Bolt, Swift Sword, and Sphere of Visibility. That’s one scary ogre!
M Blackburn: A Writer's Journey 
Frankly amazing. I was actually working something like this up myself, to further shake up monsters in Cook/Moldvay D&D. The templates in D&D3.X and 4E were never easy. This is extremely fast and easy. Well done!
Thank you for the praise! I’m really happy with how they worked out. I’m enjoying working on some more esoteric ones like Fiendish and Celestial right now. Hopefully have them up soon!