Well in the days before you had the enns chant it was still simple
Banish,
LBRP
Middle pillar
Bornless invocation
Conjuration
That’s how I initially learned it
Worked just fine, still does
I decided to get with the times and be fashionable by using the enns method. 
Never a bad idea to learn more than one method
Enns belong to the religious practice of demonolatry. They have never been a part of ceremonial magick.
I know this much is true…
I personally hate how people these days seem to assume enns are necessary for evocation. I never use them, and evoke just fine. Even Koetting doesn’t use them (in his earlier books, the only enn EA even bothers to mention is Belial’s).
Someone mentioned giving a spirit its ‘charge’. What is that exactly?
That is simply an old fashioned way of saying “tell the spirit what you want it to do.”
If you command Belial to “Protect me form all harm, physical and spiritual,” you are charging him with that task.