1. Items In a Series 3
Three or more items in a series require punctuation, usually a comma. The last two items are usually connected with a coordinating conjunction, which is always preceded by a comma.

2. 2
1. Sara opened her locker. She took out her jacket, and dropped her mittens.

3. 3
1. Sara opened her locker, took out her jacket, and dropped her mittens.

4. 4.
2. They planned the trip, and they got a bus schedule. And they took a bus to the museum.

5. 5
2. They planned the trip, got a bus schedule, and took the bus to the museum.

6. 6
3. Luis planned the party, and he called their friends. He ordered the food. Gina cleaned the recreation room, and she made decorations, and she set up the CD player.

7. 7
3. Luis planned the party, called their friends, and ordered the food, and Gina cleaned the recreation room, made decorations, and set up the CD player.

8. Parallel construction8
Series
His brother thinks of Doodle as being the scarlet ibis: It’s his way of dealing with his grief, getting a handle on his guilt, and honoring Doodle’s memory.
Doodle and the bird had many things in common: both had physical weakness such as thin legs; both die partly due to a storm; and both are red after their deaths.
Parallel construction