I've decided to scrap my grossly OP character (Conjuration 100 at level 26). But I want to keep as narrow a focus as possible while at the same time using zero followers. And I want to use Destruction as a melee weapon---IOW, I don't want to carry any weapon except a dagger and a bow. And I wanna do it on Master difficulty; and anyone who plays the game on Master knows that Destruction is horribly underpowered.

Most points will go into health and magicka, with magicka getting the majority, with zero points going into stamina (I'll get the extra pockets perk).

But I always have trouble narrowing things down because I like all the crafting skills. I'll have to have alchemy to support Destruction.I don't want to spend points in Illusion so for first strike legitimacy I'll need archery. Since I won't be having any followers I'll go with light armor so I can carry enough stuff. And I have to do Smithing... and Enchanting.

So let's see

Alchemy
Destruction
Archery
Sneak
Light Armor
Smithing

I'll throw a bone to Enchanting once in a while and maybe carry a dagger or bow with soultrap.

Thoughts?

Your already doing enchanting, no need for big pockets- or looting- to make bank.

Why would you have to put more than two perks into smithing? Steel and arcane is enough if you are going wtih minimal weapons loadout. You could also perk into Conjuration for bound weapons to save the trouble of carrying a soul trapping bow. You could cast bound bow and forget about carrying any physical bow at all. Also, don't discount Illusion's silent casting perk!

Destruction is strong even on Master if you are smart about it. By that I mean keep your level as low as possible, by using as few skills as possible. I would not recommend using Sneak/Archery/1H at all.

You'll probably want to use fire magic for the extra burning effect to maximize DPS. Take the Augmented Flames perk(s) as soon as possible. Doing this will synergize extremely well with the Fire Breath shout, which you can power up even further with meditation.

Light or even heavy armor is a wise choice. I had a lot of success using gauntlets + boots, and Destruction robes + hood. Restoration is very wise especially without a follower, and it levels slowly once you get into the 30s (which is good). This will eventually unlock the potential for Necromage Vampire, which will boost the power and duration of Fortify Destruction potions by a considerable margin if you so choose. Note that the heavy Dragon priest mask Nahkriin is -20% to both Destruction/Restoration, which you may have use for.

If you want to really optimize your level ups, you should take all HP and none of the Destruction skill related type perks past Novice, since you'll eventually have 0% gear rendering mana and reduction perks obsolete. You can get around the extremely limited mana mid-game by hotkeying a Fortify Magicka item and un/re-equipping it when you can't cast any more.

Ideally you will level all 3 crafting skills to 100 in one fell swoop. That means gathering/mining all the materials you need (ore, ingots, pelts, soul gems, souls, and ingredients) as you progress, but storing them for later use. They inflate your level too much by the time they are useful otherwise.