Choose your target texture: crisp-tender (green beans/snap peas) or tender-with-edges (broccolini/baby zucchini).
Use the ratio: aim for 1:1 for most swaps, but use ¾:1 for zucchini to avoid watery results.
Match cook time to density: quick-heat (snap peas) needs less time than long-roast veggies (green beans/broccolini).
Prep for even doneness: cut into similar thickness to your asparagus spears (about the same width).
Season after cooking (or during the last 1–2 minutes) to help prevent sogginess—then taste for salt and brightness (lemon/vinegar).