Materials you will need:
Worsted weight yarn (choose your preferred color)
Crochet hook suitable for the yarn weight (usually a 5.5 mm or 6 mm hook)
Start by making a slip knot with your yarn and create a foundation chain of the desired length. The number of chains will depend on the circumference of the hat you want to make. A typical slouch hat might require around 70-80 chains.
Once you have your foundation chain, join it in a circle by slip stitching into the first chain you made. Be careful not to twist the chain.
For the first round, crochet one chain stitch, then work one single crochet stitch into each chain around the circle. Join with a slip stitch to the first single crochet to complete the round.
For the following rounds, continue working in a spiral without joining at the end of each round. Crochet one chain stitch to start each round. Work one single crochet stitch into each single crochet from the previous round. Keep repeating this pattern until your hat reaches the desired length. For a slouchy effect, you can make it longer by adding more rounds.
Once your hat is the desired length, fasten off your yarn, leaving a long tail. Cut the yarn and pull it through the last stitch to secure it.
To create the slouchy part at the top of the hat, thread the yarn tail through your yarn needle. Insert the needle through the front loop of each stitch from the last round and pull tight. This will gather the stitches and create the slouchy effect. Secure the yarn by weaving it through a few stitches on the inside of the hat.
Finally, weave in any remaining yarn tails using your yarn needle to hide them and trim any excess yarn.