Shapes and embellishments on hats vary, but making a simple toque can be as easy as creating multiple rounds of single crochet starting from the brim, and then decreasing stitch numbers regularly at the top for the crown. Patterns can be found online at AllFreeCrochet.com or via searches on Pinterest.
Gather appropriate supplies before beginning the hat. It is easiest to source the same or comparable materials as called for by the pattern, particularly with regard to the yarn weight and type. Heavier yarns are hard for a baby's head to support, and certain types of fibres, such as wool, might cause itchiness or even a rash.
Circumference for infant hats ranges from eleven to about fifteen inches. Depending on the stitch used, the hat will stretch more or less when it is finished. If working from a pattern, you will have a specific gauge to crochet to. If working without a pattern, measure the infant's head, then knit a swatch to test for stretch and take this into account when planning measurements.
Crocheted hats are typically knitted in rounds. Some patterns call for joining the rounds with a slip stitch, but many do not. Either way, a crocheted hat is a simple project.