Decide your dish type: roasting/sautéing, soup, or purée—this determines whether you need drier or creamier flesh.
Choose the closest substitute from the list, aiming for similar sweetness and how firm the raw flesh feels.
Use the swap ratio for your recipe amount; for wetter substitutes (pumpkin), roast/steam first to reduce moisture.
Adjust doneness: squash should turn fork-tender; keep sweet potato slightly firmer if you plan to roast.
Season after cooking (especially salt/umami) so the substitute’s flavor doesn’t taste flat compared to kabocha.