Staves, quest items and some unique items cannot be disenchanted. (Example; Staff of Fireballs, & Dragon Priest masks.)
Helms can be found with resistance to elements as loot, but an enchanter cannot make a helm with elemental resistance. The same "rule" also applies for carry weight and other enchantments; You can find items in game that the player can not make.
The Player is able to rename their enchanted items, so they can easily identify their different custom handcrafted items. Also, If you put a space in front of the name it will always be at the top of the list.
With the perk Extra Effect the player can choose up to two different enchantments for one item in enchantment selection. The enchantments must be different, i.e. you cannot stack two + healths or two fortify magics. The power of enchantments will be determined by the size of the Soul Gem used and not be influenced by each other. For example you can enchant both a +40% One-Handed Damage enchant and a +25 Light Armor enchant without affecting their strength.
Enchanting "Fortify <magic school>" at 100 skill level and 5/5 Enchanter perk with a Grand soul results in a 25% casting cost reduction for that school. This stacks additively; meaning that with 4 items (chest, ring, amulet and head) you can cast spells in that school for free. Combined with the perk Extra Effect, players can cast spells from up to two schools for free with the same gear set.
The easiest way to capture souls is to use a perk point to unlock soul trap with bound weapons, then use a bow while sneaking from a distance. Bound Bows come with 100 bound arrows which replenish when the bow is resummoned, and just having it out levels Conjuration further.
Also for the advanced conjurers, travel into The Midden under the College of Winterhold to find the Atronach Forge. Read the book nearby for instructions, and enjoy. Here you can "forge" daedric hearts, daedras, atronachs, staffs, etc.. and capture all the Grand Souls you want. Black star or regular Azuras Star will work here.
You cannot remove an enchantment once it is placed. Be careful with your Daedric Armor!
For enchants that have two effects, e.g. Fiery Soul Trap, The second effect is constant and the number of charges is based on the first effect. This means that you can set it to one second soul trap and still keep the +10 fire damage. With a grand soul you can get over 2000 charges of +10 fire damage using Firey Soul Trap, but you would only be able to get around 50 charges if you used the Fire Damage enchant to get the same +10 Damage. It is very useful for characters that don't have any enchanting skill.