Some crochet stitches seem to be more difficult than others--but they don't have to be scary. The front post double crochet (fpdc) is one of those stitches that you might shy away from. I'm going to show what to look for when you are working in rounds because it's a little different than when you work in rows.
First, let's look at a row. When you insert your hook in a stitch in a row, your hook is inserted just a little to the left of the stitch you will be working. In the photo, looking at the stitch inside the rectangle, the arrow is pointing to where you will insert your hook for that stitch.
However, when you work in rounds, you will insert your hook just to the right of the stitch you are working, as shown in this photo.
To make the fpdc stitch, you yarn over, then insert your hook behind the post of the stitch you are working, yarn over again and pull your hook through to the front of your piece and finish just like a double crochet, yo, pull through two loops, yo, pull through remaining two loops.
You can see in the photo to the left, you do not insert your hook into the top of the stitch; the stitch is made around the post only.
If the next stitch is a double crochet, you want to be careful where you insert your hook. You don't want to insert your hook into the top of the stitch where you just made the fpdc.
Sometimes the top of the next stitch is slightly hidden by the completed fpdc, just remember that you insert your hook to the right of the stitch you will work and that should help you find where you need to insert your hook. See photo below.
Increasing stitches in the round, requires that you make two stitches in the same stitch.The instructions might say to make two fpdc in the same stitch, in this case, you would make two fpdc around the same post. Or the instructions might say to make a half double crochet and fpdc in the same stitch. In that case, you would make a half double crochet in the top of the stitch and the fpdc around the post of the same stitch.
Crochet ribbing can be made by crocheting double crochet and fpdc stitches, When you alternate, fpdc, and another stitch, like double crochet, be sure you don't make your fpdc around the post of the double crochet stitch. In this photo, you can see that the double crochet stitch is between the two fpdc.
I hope this has answered some of your questions about the front post double crochet stitch and crocheting in the round.
Now go out in confidence and crochet!