Buy a ‘Conjure Flame Atronach’ spell

Woodcutter's Camp at Lake Geir, Altar in the Woods at Autumnshade, and there's a spot near Darklight Tower. Look for dead trees.

In the Dragonborn DLC, the Tel Mithryn quests are mostly mage-related. Lore-wise, this is because Neloth, which is related to and gives most of the quests, is a wizard lord from House Telvanni, one of the Great Houses of Morrowind. House Telvanni is comprised mainly of mages.

• Azra's Staffs: Retrieve a staff made by Azra Nightwielder for Master Neloth.
• Briarheart Necropsy: Examine a Briarheart of the Forsworn for Neloth.
• Experimental Subject: Help Neloth by being a test subject in his experiment.
• From the Ashes: Help Talvas Fathryon by killing an ash guardian.
• Healing a House: Help Elynea Mothren repair the tower of Tel Mithryn.
• Heart Stones: Find a heart stone for Neloth.
• Lost Knowledge: Retrieve the Black Book for Neloth.
• A New Debt: Help Drovas Relvi with his debt to Mogrul.
• Old Friends: Find the source of attacks on Tel Mithryn.
• Reluctant Steward: Find a new steward for Neloth in Raven Rock.
• Telvanni Research: Extract a sample from an ash spawn for Neloth's research.
• Wind and Sand: Retrieve a copy of Wind and Sand for Neloth.

^{Source: UESP wiki, "Dragonborn quests" article}