1. Punctuation Rules
Coordinating Conjunctions (and, but, or, yet, so):  Put a comma before these conjunctions. (Don't use them at the beginning of a sentence)
example: The movie has already started, but my friend has not arrived yet.
Correlative Conjunctions (These have two parts: either or):
Put a comma before the second part if it connects 2 independent clauses (complete sentences). 
example: Eric is not only an outstanding teacher, but he is also a gourmet cook.
You don't need a comma if it only connects words or phrases. 
example: Eric is not only an outstanding teacher but also a gourmet cook.

2. Punctuation Rules
Transitional Words and Phrases:
Put a comma after these if they are at the beginning of a sentence. 
example: I like to travel. Specifically, I enjoy places with old cathedrals.
Use a semicolon to connect the two sentences. 
example: I like to travel; specifically, I enjoy places with old cathedrals.
Use a comma before and after the transitional word/phrase in the middle of a clause. 
example: I like to travel, and, specifically, I enjoy places with old cathedrals.

3. Conjunctions (and, but, or, yet, so)
Put a comma before these conjunctions. (Don't use them at the beginning of a sentence) Example: The movie has already started, but my friend has not arrived yet. Formula: S,C,S
IC/sentence
IC/sentence

4. Transitional Words and Phrases
Use a semicolon to connect the two sentences. Example: I like to travel; I enjoy places with old cathedrals. Formula: S;S
IC/sentence
IC/sentence

5. Transitional Words and Phrases
Put a comma after these if they are at the
beginning of a sentence. 
Example: Specifically, I enjoy places with old
cathedrals.
When I travel in Europe, I visit old cathedrals.
Formula: T,S
Transition Word
IC/sentence
Transitional Phrase
IC/sentence

6. Transitional Words and Phrases
Use a comma before and after the transitional word/phrase in the middle of a clause. 
Example: 
I like to travel, and, specifically, I enjoy places with old cathedrals.
Specifically, I like to travel and enjoy places with old
cathedrals.
Formula: S,C,T,S
IC/sentence
Conj.
Transition Word
IC/sentence
Transition Word
IC/sentence
DC/incomplete sentence

7. Punctuation Formulas
S,CS – Sentence + Comma + Conjunction + Sentence T,S – Transition Word/Phase + Comma + Sentence S,C,T,S – Sentence + Comma + Conjunction + Comma + Sentence