Level up your alchemy by making expensive potions and invest points into your alchemy skill tree.

There’s also two more ways to increase your numbers:

The legitimate way:
Learn the fortify alchemy enchantment. Use some grand/black soul gems to create a set of armor (I think gauntlets, helmet, and jewelry) with the fortify alchemy enchantment. Brew a fortify enchantment potion while wearing that armor (I highly recommend a mod to increase the potion duration). Drink the potion and enchant a new set of armor. You’ll start building up a big buff after a few times of this. You can also brew a potion for smithing for better armor and weapons.

The illegitimate way:
Enchantments are counted as restoration magic. Fortify restoration potions affect the armor enchantment bonuses too. Take a potion and put your armor on and now it’s buffed by the potion effects too. There’s a bug that allows the bonuses from the potion to persist after the effects should have worn off. A quick lookup shows this:

If your character has an Alchemy level of at least 40, the Benefactor perk in the Alchemy skill tree, and four pieces of armor with at least 8% Fortify Alchemy Enchantments on them

This will allow you to make some insane armor and weapons by abusing this glitch.