Foundation stitches can be used instead of making a number of chains and then working stitches into the chains. This will be when you are working in rows.
The basic principal is the same no matter which foundation stitch you are making, Foundation Single Crochet [fsc], Foundation Half Double Crochet [fhdc], or Foundation Double Crochet [fdc].
Each height of stitch starts with a slip knot on your hook, and then chain 2.
These chains do not count as a stitch, they are only to get you started.
You will then make a chain for the stitch to sit on, and then make your stitch.
To make Foundation Single Crochet
1. Begin with a slip knot on your hook.
2. Chain 2, these chains do not count as a stitch.
3. Put hook through 1st chain.
4. Yarn over.
5. Pull through a loop.
6. Yarn over.
7. Pull through a loop, making your chain for the base of the stitch.
8. Yarn over.
9. Pull through both loops on hook to make your single crochet.
10. Continue, making sure you put your hook under both loops of the previous chain.
11. Pull up a loop, and make a chain, then complete your stitch.
12. Continue until you have the required number of single crochet stitches.
13. The top of your row will look the same as a normal row of single crochet stitches.
14. The bottom of your foundation row will have a neat edge, which can easily be worked into for joining, or gives a beautiful finished edge to the bottom of your work.
To make Foundation Half Double Crochet
1. Yarn over.
2. Put hook through previous chain.
3. Pull up a loop.
4. Make a chain.
5. Yarn over and pull through all 3 loops to complete your stitch.
6. Continue to make as many hdc as you need.
To make Foundation Double Crochet
Work as for foundation half double crochet, but make your double crochet stitch as normal by making a yarn over and pull through 2 loops twice.
The main problem people have with making foundation stitches is that the piece curves.
This is caused when you forget to make the chain stitch at the bottom or making the cain stitches too tight.
I hope you have found this helpful