Press the touch pad to bring up the crafting menu. Use the directional buttons to select an item to craft, then hold the X button to craft an item. Recipes that currently have enough ingredients to be crafted are marked with a wrench icon in the top left corner. If Text-to-Speech is enabled the word "Craftable" will be spoken after the item name.
Some items can also be crafted directly from the weapon cross. Use the directional buttons to bring up the weapon cross, then hold X to craft the selected item (when available).