Generally, for a more texturized and piecy look, products like pomade, wax, cream, and muds are used.
Though all these may sound like a frenzy of products, it really goes to state using a more tacky, thick, and even gummy product that allows for separation and definition without a hardened, crunchy feel or look.
The weight and feel of these products may vary between brands, what one line may call a "wax", another line may deem a product of similar feel a "pomade".
Products like these work best on hair that is layered, the more layers, the more definition can br brought out. It's also easier to work with these products on shorter hair as the formulas are denser, using the formula on longer hair would result in a lifeless form as too much would have to be used and the eventual outcome wouldn't be as clean or precise looking as someone who's length is shorter.
Take a pear sized to dime sized amount of product, work it through your hands to warm up the product and apply it through hair evenly for an all over, piecy look. For a more minimial or precise look, apply product on fingertips while twisting and grabbing at the ends of hair or smaller areas so just the tips are more defined.
For long hair, to create messy texture, reach for a salt spray, though several brands create premade formulas, you can also make your own with dozens of formulas found online. The plus side of premade salt sprays is they often come with hair conditioners infused as well so you're not over drying your hair with use. Salt is great for creating volume, enhancing texture, and giving hair a nice, beachy waved look.