Step 1

YO

Step 2

insert hook in next stitch, yo

Step 3

pull through and bring yarn up to height of rest of stitches (3 loops on hook)

Step 4

YO

Step 5

insert hook in SAME stitch, yo

Step 6

pull through and bring yarn up to height of rest of stitches (5 loops on hook)

Step 7

YO

Step 8

insert hook once again into the SAME stitch, yo

Step 9

pull through and bring yarn up to height of rest of stitches (7 loops on hook)

Note: If you want your puff to be larger repeat step 7 -9 again for 9 loops on hook

Step 10A-1

Here's where you can veer off. There are a couple different ways to complete the puff.

Method A is shown here:
yo, draw through 6 loops

Step 10A-2

yo, draw through remaining 2 loops
Puff Stitch complete

This picture shows the larger puff with 9 loops. At Step 9 if you repeated steps 7 and 8, this is what you would have.

Here we have 7 loops on hook as in Step 9 above. YO (not shown)
 

Pull yarn through ALL loops on hook

Just to how you how the puff works next to other stitches, I've put a double crochet in the next stitch. This is not actually part of making the puff.