Sure, here’s a basic description of how to crochet a corner-to-corner (C2C) square using a free pattern:

Materials Needed:

  • Worsted weight yarn in your choice of colors
  • Crochet hook appropriate for your chosen yarn (typically size H/5.00mm)
  • Scissors
  • Yarn needle for weaving in ends

Abbreviations:

  • Ch: Chain
  • Dc: Double crochet
  • Sl st: Slip stitch
  • St: Stitch

Instructions:

Step 1: Starting Point

  1. Make a slip knot and chain 6.
  2. Double crochet (dc) in the 4th chain from the hook (counts as your first 3 dc).
  3. Dc in the next 2 chains.
  4. You have completed your first block.

Step 2: Increasing Rows

  1. Ch 6.
  2. Turn your work.
  3. Dc in the 4th chain from the hook and in the next 2 chains (this creates your next block).
  4. Slip stitch into the ch-3 space of the previous block.
  5. Ch 3 (counts as your first dc of the next block).
  6. Work 3 dc into the same ch-3 space.
  7. Repeat steps 2-6 until your row has reached your desired width.

Step 3: Decreasing Rows

  1. To start decreasing, slip stitch into the first 3 dc of the last block made.
  2. Ch 3.
  3. Work 3 dc in the same space.
  4. Slip stitch into the ch-3 space of the previous block.
  5. Ch 3 and work 3 dc into the same ch-3 space.
  6. Repeat steps 1-5 until you have reached your desired square size.

Step 4: Edging (Optional) You can add an edging to your square to give it a finished look. You can use a simple single crochet (sc) or a decorative border like shells or picots.

Step 5: Finishing

  1. Fasten off your yarn, leaving a tail for weaving in.
  2. Weave in all ends using a yarn needle.

Tips:

  • As you continue, your work will form a diagonal square. The increasing rows will build up one side, and the decreasing rows will build down the other side.
  • You can change colors at any point to create stripes or patterns.
  • This corner-to-corner technique can be used for various projects like blankets, scarves, and more.

Remember that this is a basic description of a corner-to-corner square pattern. You might want to refer to a more detailed tutorial or video for step-by-step visuals. Additionally, make sure to adjust the number of chains and stitches according to your desired size and the yarn and hook you are using.