I am considering going back to Morrowind in the near future, this time making an Enchantress. Basically, the character will be a female character whose main skill is Enchant. (Part of the reason for choosing this is that Morrowind is more amenable to this sort of build than Oblivion, which doesn't even have an Enchant skill in the first place.)

What sort of race, class, and birthsign, in your opinion, do you think would work best here?

If going with the premade classes only and with a focus on Enchant, a Breton Sorcerer born under The Lady seems like the primary pick. You'll have a slightly larger than average pool of Magicka for spells, but Bretons are also decent with weapons. Sorcerers having Heavy & Medium Armor as Minor Skills mean that they have a natural inclination towards the Armor pieces that have the best Enchant capacity. The Lady will provide you with more starting Health and make people less hateful towards you.

Alternatives would be Altmer, Witchhunter and/or The Mage. Altmer and The Mage are for a more spell focused path and both do work well with Sorcerer. Compared to Sorcerer, Witchhunter emphasizes weapon skills a bit more and also uses Light Armor instead of Medium/Heavy.

A few thoughts on this:

Altmer and Breton suffer from having low Strength. Given that the items capable of the best enchantments can get pretty heavy (Daedric Tower Shields, in particular, have 45 weight), this can be a problem.

Heavy Armor is a decent option due to such items being nicely enchantable. On the other hand, the Boots of Blinding Speed (which are quite useful) are considered Light Armor.

I will likely be using a custom class, with Enchant as a major skill. I am thinking that Restoration and Conjuration might be good to have; Restoration to fortify stats and skills (especially since the same stat/skill can be fortified multiple times in one spell, and doing so gets expensive quickly with enchantments but not spells), and Conjuration to summon creatures to trap their souls (in particular, Summon Golden Saint might not be easy to fit on an item that isn't too heavy). Maybe Mysticism as minor?

Race-wise, I actually think Orc might be a good choice; good starting Strength and Endurance, while Intelligence (for females) and Willpower aren't that bad. On the other hand, I don't get any Enchant bonus with this race (and Enchant levels up very slowly).

I was actually thinking Atronach for the birthsign; the spell absorption and extra Magicka are nice for when I need it, and Stunted Magicka is mitigated by the fact that item charges recover on their own. Also, summoning Ancestor Ghosts and turning them hostile can allow Magicka to recover in the wilderness.

I am thinking that Strength (for carrying capacity) and Endurance (for HP) are the stats to focus on at first. Should my class use those stats, or should I replace Strength with Luck? (Endurance is important because, unless I decide to use the Code Patch or do silly exploits with Drain Stat + Fortify Fatigue, you really can't use magic to fix low Health.)

Nord is a good race for this build; I have recently done a similar build. Nords have high strength and endurance plus excellent resistances. With a few easy-to-get items you can have 100% resistance to frost, shock and either fire or magicka while still taking Lady for the boosts. You don't need much magicka because you don't really need any other magic skills except Alchemy and Restoration. The starting axe bonus is also very useful for the first few levels before you can start making enchanted items.

One other question: What should my primary weapon skill be? I am thinking that Blunt Weapon might be a good choice since there is a staff with 90 enchant points, though the downside is that there are fewer pre-enchanted weapons of that type than there are of Long Blades. Plus, this boosts Strength. (Remember: I am going Heavy Armor, which will improve Endurance.)

I would use the code patch. Without it, I've found enchanting items yourself to have very low odds, and hiring an enchanter is ridiculously expensive.

Plus, without the code patch, your enchanted items are worth exactly the same as their mundane counterparts.

I am actually currently planning *not* to use the code patch; with the help of Restoration and Fortify Skill, I can make almost any enchantment on my own.

If I do use the code patch, I am thinking I might only apply what I call critical fixes, and *maybe* the Fortify Health tweak. (In particular, I do not plan on using things like the blind fix.)

Anyway, I still want to know what weapon skill would be best to invest in for this character; is Blunt a good choice?

My character is tentatively looking like the following. How does this look? Or should I consider Illusion? (How useful is Illusion in Morrowind anyway? I know it's really good in Oblivion (to the point of being game breaking, to be honest), but I have never used it in Morrowind.)

Yes, Illusion is great in MW as is it's associated attribute, Personality. You can make a whole build around Personality and its skills. At 150 Personality (surprisingly easy to get because of a certain helm) no one will attack you so you can control any situation either as a pacifist or an opportunist.

Illusion can be at least as game breaking in Morrowind as in Oblivion.

Chameleon at 100% breaks the game in much the same way, but requires more pieces of enchanted gear than in Oblivion (on the other hand, you can equip more gear than in Oblivion). Sanctuary can also break combat at 100. Charm with high magnitude & low duration makes disposition pointless. Calm Humanoid can be used to talk to otherwise hostile people, while Frenzy can make someone else attack you (avoiding an Assault bounty).