To cut down on time for making NPC's and stuff (for the main villain that is), the easiest way to do something like that would be to first, never worry about skills. If you plan on having them be killed by the party, skills are the least important. If a skill check actually needs to come up, the easiest DM rule for that would be their level + their score for that skill (note, the max is level + 3 for ranks in skill, well that would make it occasionally unfair if they have to make skill checks for ten or twenty different skills. Use just their level to even things out).
In terms of spells, unless you need them to be specific mages, like wayfarers or protect-spell mages, go all out attack spells. Magic missile, scorching ray, fireball, wall of fire, and cone of cold, etc. If it's the generic mage, you don't even need to write any more known or scribed spellbook spells, just those five would be sufficient. The rule that this Npc is most likely going to die also applies here, so like I said, if you don't want it to die, maybe pay attention to spells.
Equipment, just use the DMG equipment list. Each level of each core class in the players handbook has equipment statted out for NPC's in the Dungeon masters guide. Saves a tremendous amount of time.
In terms of weaponry, Warriors always get longswords, Spellcasters always have quarterstaves, rogues always have short swords, and priests always have maces, no need to ever detract from that as it's good enough alone.
Good filler feats: Alertness, Improved Initiative, Quick Draw, Spell Focus, Combat Casting. These are feats that you put their just because you couldn't think of something better.
Never have an NPC warrior get cleave or great cleave for feats. Completely useless.
Never use prestige classes or multiclass. Average their hit points, much faster than rolling. Standard NPC's and Monsters have an ability point buy score of 25 points, most commonly this is 15, 14, 13, 12, 10, and 8, this is also an average and it's best to simply stick with those scores.
When making a mini-boss like creature of an NPC battallion, such as a Chieftan in a small tribe of orcs, the stronger creature is always 1.5x the level of the cannon fodder, and of the same class. Meaning, if you have ten fourth level orcs, the chieftan of that small tribe would be sixth level.
Some of these suggestions you might already use, but this is the easiest way to create NPC's that you don't give a crap about. It takes maybe ten minutes per character, so long as you have a character sheet template on your computer notepad or something.
If you'd like mine-
NPC Template
Race-
Class-
HP-
Init-
AC-
Speed-
Str-
Dex-
Con-
Int-
Wis-
Cha-
Base Attack/Grapple-
Attack-
Saves-
For-
Ref-
Wil-
Feats-
Spells-
Equipment-