Custom class, combat, endurance and luck
Major skills: Alchemy, Conjuration, Restoration, Security, Sneak, Acrobatics, Speechcraft
Starting stats: Str 50, Int 30, Will 30, Agi 50, Spd 50, End 55, Pers 30, Luck 65.
STEP ONE: Get Endurance to 100 in the minimum number of levels possible. Ideally I begin by using Restoration, because I'll be needing it anyway to heal up while using Block and Heavy Armor regularly. Restoration maxes out at level 8, when Endurance is at 90. This would be a good time to put some points into Speechcraft, I think. Endurance maxes at level 10.
END OF STEP ONE: Str 50, Int 30, Will 65, Agi 50, Spd 50, End 100, Pers 40, Luck 74.
STEP TWO: Now I work on my Alchemy as a major skill. Selling off my potions should raise Mercantile, and if Mercantile isn't going fast enough, I can also put points into Illusion. Alchemy hits 95 at level 17.
END OF STEP TWO: Str 50, Int 65, Will 65, Agi 50, Spd 50, End 100, Pers 75, Luck 81.
STEP THREE: Acrobatics is the third major skill to use. It hits 95 at level 24. I'm also going to put points into strength at this time.
END OF STEP THREE: Str 85, Int 65, Will 65, Agi 50, Spd 85, End 100, Pers 75, Luck 88.
STEP FOUR: Sneak is the next major skill to go and will hit 95 at level 31. I will first go ahead and finish up strength through levels 25-27, then move on to Destruction and Alteration to raise my Willpower from 28-31.
END OF STEP FOUR: Str 100, Int 65, Will 85, Agi 85, Spd 85, End 100, Pers 75, Luck 95.
STEP FIVE: Now I return to Speechcraft as my major skill to get Personality up, using Mysticism as the minor skill for my Intelligence. I should still have enough Speech points left to get to level 36 (when Luck maxes out), but if not, I can always do a combo of Illusion/Mercantile as a minor with a major in Conjuration.
END OF STEP FIVE: Str 100, Int 90, Will 85, Agi 85, Spd 85, End 100, Pers 100, Luck 100.
STEP SIX: Security is an excellent major skill to start with. Take that three levels to max Agility, wear Light Armor and get hit a lot for a minor in Speed, and continue Alteration/Destruction minors for Willpower.
END OF STEP SIX: Str 100, Int 90, Will 100, Agi 100, Spd 100, End 100, Pers 100, Luck 100.
STEP SEVEN: Only need to raise intelligence twice. Ideally I can even just use Conjuration as a major skill; if not, any combination of Alchemy/Conjuration/Mysticism for ten points at a time will work with any other major skills filling in the blanks to level. At the very least I should still have a LOT of potential security training to do.
END OF STEP SEVEN: All attributes max out at level 41.
QUEST TIMING NOTES:
Immediately head up to Aleswell to do quest for a free bed and non-respawning chest to keep awesome stuff in until Hiccup can afford a house of his own. Then do Go Fish in Weye and A Brush With Death in Cheydinhal.
Immediately after hitting level two (so as to not interfere too much with my skill training), do Deliver the Amulet and the Kvatch quests before the battle gets too tough. The leveled reward doesn't really matter much with efficient leveling, he'll be maxed out soon enough anyway and it will be little use. Just a souvenir!
After that, stash Martin somewhere safe (he just gets in the way of leveling, really) and do The Desolate Mine (Cheydinhal Fighters' Guild quest) and The Killing Field (Chorrol) so the NPCs don't die. Then head for Leyawiin to do the Mazoga quests.
Do Daedric shrine quests as soon as they become available. (Make sure to do Ahdarji's Heirloom before Sanguine.)
Origin of the Gray Prince gives +3 to Athletics, Block, and Blade. This will be most useful before level 10 while still working on Endurance, for the Block bonus. The Arena can also be completed around this time to get it out of the way (and it might help with Block/Armorer/Heavy Armor too, who knows).
Do The Collector and A Venerable Vintage whenever there's a significant lull, but preferably while training for something that will rise while attacking stuff. Maybe during Endurance.
Two Sides of the Coin (in Bruma) gives a really nice silver longsword (MY BABY) that I'll want early.
I get into Destruction at level 28 - good time to go kill Umbra.