Now, the noodles. Please, for the love of all things holy, overlap them slightly. Think of them like roof shingles. A single layer of noodles with gaps is a guarantee of structural failure. Your ricotta will seep through and make a break for it.
You want a solid, continuous plane. If you’re using no-boil noodles, they need a bath of sauce to soften up. Don't be stingy. Imagine they are thirsty little sponges. They don't want a drizzle; they want a soak.
I used to lay my noodles perfectly, without overlapping, like I was making a puzzle. The result was always a lasagna with mysterious empty tunnels. It was like a Swiss cheese version of itself, full of holes and regrets.
What Is The Layer Order For Lasagna at Eva Melendez blog