Identify your use case: raw crunch (salads/sandwiches) vs quick pickles vs mixed into sauces.
Choose the substitute by texture: English/pickling cucumber for closest bite, jicama for maximum crunch, zucchini only if you can salt + blot.
Prep for the right moisture: salt then blot zucchini; drain and rinse pickles; peel jicama for the cleanest mouthfeel.
Season to match cucumber’s mildness: add a little extra salt for zucchini/pepper, or add a touch of sugar if your swap is too sharp.
Use thinner cuts for the closest cucumber experience—aim for matchsticks or paper-thin slices depending on your dish.