I am level 48 in conjuration and need to get to 100. I know one way to speed it up, but it's not that fast.
Casting spells in combat gives skill xp equal to the base cost of the spell.
If you use a Weapon spell, you can't recast while the weapon is out. Sheath it to cancel the spell, allowing the next cast.
If you use a Summon spell, it might kill the enemy, ending your combat, requiring you to search out another enemy to gain skill on.
If you use a Target spell, it must connect with a target to award skill xp.
SpellType Spell Name BaseCost Required Skill Weapon Bound Sword 93 0 Weapon Bound BattleAxe 169 25 Weapon Bound Bow 207 50 Summon Conjure Familiar 107 0 Summon Conjure Flame Atronarch 150 25 Summon Conjure Frost Atronarch 215 50 Summon Conjure Dremora Lord 358 75 Target Soul Trap 107 25 Target Banish Daedra 196 50 Target Command Daedra 243 75
So - to gain skill xp the fastest - enter combat and cast the most expensive conjuration spell you can. There are many good choices for spells, the problem becomes more about having enough magicka to cast it again. Use conjuration enchanted gear to modify conjuration costs (if you can get to 100% free cost, that's ideal). Use the Elf racial to regen magicka. Use potions. Take the 50% discount perks.
The UESP pages for a given spell class always give good tips for gaining XP fast. Here is the one for Conjuration.
A couple of tricks that I'll highlight as being particularly easy:
- Cast Soul Trap on your horse. They don't mind, and it's free skill XP.
- Get on the shore where you know there are some hostile fish in the water. Cast Bound Sword repeatedly.
- Summoning creatures and fighting them can give you skill XP, although you can't soul trap summoned creatures in this game.
- If you've cleared the Dark Brotherhood quest line, there are some "hostile" guards in Solitude who will never actually attack you. You are counted as being "in combat" around them, so you can cast things like Bound Sword and so forth and get credit.
Buy bound sword from Farengar in Dragonsreach and fast travel to the guardian stones. Chop some wood for Alvor in Riverwood or make some valuable potions to sell to Arcadia if you need cash.
Salmon roe, Garlic, and Nordic Barnacle is the most expensive combo possible if you have Hearthfire. Get salmon roe from leaping salmon in the river between Whiterun and Riverwood. Garlic can be taken for free from Carlotta's stall if you talk to Mikail in the Bannered Mare about her. Nordic barnacle can be found in the pools outside Dragonsreach. If you don't have Hearthfire, you can mix blue butterfly wing and blue mountain flower. The former can be found during the day around Whiterun, particularly at the crossroads by Honningbrew Meadery and between its buildings. Enter and exit the meadery for them to respawn. The exact mix of butterflies is random but usually has 3, either all 3 the same or 2 of 1 and 1 of the other. The latter can be found on the road between Windhelm and Morthal, north of Whiterun. You can even find some extra on the way up there. Start at the crossroads by the meadery and head north. There should be some as you approach the northern east west road. There is a massive butterfly spawn around Stone Hills if you go that far West toward Morthal.
Activate the Mage Stone and head out into the lake. A small island with the Lady Stone is in the midst of the lake. Hopefully you will attract the attention of some slaughterfish on your way to the island.
Once on the island, equip your mage robe and hood(you did pick the lock on that cage in Helgen, right? If not you can get both a better robe and hood by starting House of Horrors in Markarth. Just talk to Vigilant Tyranus outside the abandoned house). Read the bound sword spell tome and equip the spell to both hands. Cast it in both hands at the same time with a slight delay between hands.
Sheathe swords and repeat(helps if you have the novice perk in conjuration). The bound sword spell grants over 5 times its magicka cost in xp(469xp versus 93 magicka cost).