Combine the zucchini and yellow squash in a colander in the sink and sprinkle 1 tablespoon of the salt over it. Toss to coat, and set aside for 10 to 15 minutes, no longer.

In a large bowl, combine the garlic and shallot, sprinkle with the remaining ¼ teaspoon salt, and whisk in the lemon zest and juice. Whisk in the olive oil in a steady stream, then the almonds and dill. Taste for seasoning and acidity (it should be nicely acidic). Add the zucchini and squash to the dressing, toss, and serve immediately.