I mainly make stealth-based characters and thought i should try out a magic user. Right now I'm level 21 and trying to use illusion, destruction, and getting necro mage perk since i turned into a filthy bloodsvcker. I am also going down blocking to help with some close combat though, it works kinda wonky but I started it so im going to finish with it!
Anyone have any tips for me?
Thanks in advance!

Well, it depends how you like to play. With my first mage character I felt I got svcked into being a destruction mage, since that's the only way you can kill anything during the intro. It was difficult to switch paths afterwards as my other skills were undeveloped, but if I tried to increase them rather than destruction, my destruction skills also fell behind, and I was thrashed. But as there is not a lot of strategy involved with destruction, I got bored quite quickly.

I did really enjoy playing a full-on Illusionist healer - Harmony is awesome, and I rather liked rushing round Rallying the townspeople against dragons rather than fighting them myself. You pretty much have to get all the Illusion perks and spells and Necromage as soon as you can, though - and avoid raising any other skill much (or going into barrows) until you have.

I found myself suffewring from the same problem. On my second charachter I decided to take a different route, I incisted in alteration which was realy fun. One of the spells you unlock is realy effective for a pure mage charachter, paralize stops melee enemies in their tracks along with most enimies making them vunerable to attack. Also mage armour realy helps to protect you considering that a mage charachter has low health.

I would recommend not duel wielding destruction magic but use one hand for destruction and the other hand for anything else you might want to increase.

Conjured weapons is a good path to take. I'm playing as a necromancer vamp in anticipation of the DLC. Sticking to my Conjuration spells as often as possible without using destruction too much, along with illusion and restoration, with a little alteration thrown in. As long as there are multiple enemies, Illusion works wonders.

Like Ingenue was saying just watch what skills you are leveling so you dont get to the point that you are weaker than the leveled enemies.