How to make an invisible crochet decrease

1. Insert hook in the front loop only of the next stitch

2. Then repeat in a second stitch: Insert the hook in the front loop only of the next stitch.

3. Yarn over and draw the yarn through both stitches (the first two loops on the hook).

4. Yarn over and draw the yarn through both loops on hook to finish your single crochet. You can also use this invisible decrease technique with any other type of stitches.

You can also see this video about invisible crochet decrease (in french only):