Proper Forms

There are 4 main forms.

First, there is the basic one I have mentioned. This one connects two ideas.
Independent Clause; Conjunctive Adverb, Independent Clause.
Ex. I do not hate you; however, if I had to choose between saving you or a random stranger from getting eaten by sharks, I'd save the stranger.

Next, there is a case where it introduces the independent clause.
Conjunctive Adverb, Independent Clause.
The comma is 100% required in this.
Ex. Instead, she chose to wait for the iPhone 6.

After that, there is a case where it interrupts the independent clause.
Indepen(,Conjunctive Adverb,)dent Clause
This interruption can go anywhere in the middle of the sentence as long as it is adding information to the word near it.
Ex. He rejected her 9 times. She, nevertheless, continued to ask him to be her partner.
If the interruption is weak, a comma is not required.
Ex. She will therefore have to find another partner.

Last, there is a case where it concludes the independent clause.
Independent Clause, Conjunctive Adverb

Ex. She may pull my hair and throw grape juice on my homework, but I love her, nevertheless.