Hello, I was wondering if there was any other way of boosting my destruction spells other than potions and turning the diffuculty settings to "Novice" (I like being overpowered haha).

Here is some way from http://www.uesp.net/wiki/Skyrim:Destruction:

The skills don't increase the damage of your spells, they only lower the cost.

You can take perks to increase damage to your destruction spells. You can improve your fireball's damage by 50% by taking 2 perks of Augmented Flames.

You can increase your fire damage by another 10 points by taking Aspect of Terror perk in the Illusion tree.

Potion is really your best way. I think you get 100-150% Fortify Destruction potions. And you can poison your opponent with Weakness to Magic and Weakness to Fire potions to quadruple the damage again. If you don't mind cheating, you can make ridiculously strong potions like 2000% fortify destruction with the Fortify Restoration trick.

You don't even need potions, I play on master using destruction right up to level 60+. You need to sort out the huge magicka cost of the adept/expert/master spells, I find a destruction reduction of around 80% does the trick. Then you will find (if you ignore idiots on this forum) that the damage is more than enough, 4 dual casted incinerates on master drops a deathlord.

Honestly even though you don't need fortify destruction potions I use them all the time with my mage since they're so easy to make and are effective with no perks invested. Good for dragons and large groups of enemies. I buy them from stores too since I rarely have anything else to spend money on. I usually carry 5 on me at any given time and help in tight spots.

If your lucky you can do the mages guild shalindors insight quests. You always get 3 scrolls that buff a certain school and sometimes its for destruction I always do one of those quests while im out doing other quests since they're easy and the scroll are pretty nice for a mage. There better for people who use a lot of schools of magic so you don't get useless scrolls.

That's one of the grievances that people have with Destruction compared to other kill skills: the significant lopside in the methods available to increase Destruction damage.

Put a fire spell in one hand and an axe in the other. Only use the axe.

You can enchant. Or if you're on PC you can pick up the Magic Scaling Mod(Love this mod).

Just switch the difficulty to Novice and introduce Shadowmere to bucketfuls of pain. It worked for me when I wanted to RP a Demigod character.