Let the noodles get a little dry in the colander so the sauce doesnt slip through.

I have thought ALOT about this.
I make sauce with veggies in a wide large pan.
Turn off the heat.
Transfer the pasta into the sauce (not the other way around) and Toss
Then add parmesan, fresh parsley, etc.
Final Toss and you are done. Use tongs to transfer into individual portions.

When I make a salad, I dress and toss the greens first. Once they're well coated, I add in the other ingredients and only do a little bit of mixing. Everything ends up well dressed and well distributed.

For a chunky pasta sauce, maybe the procedure would be to thoroughly toss a small amount of sauce and then not-so-thoroughly mix in a larger portion of sauce.

Sometimes this is more a conflict between the shape of pasta and the pieces of yummy bits that we mix in. I find that long noodles (spaghetti, angel hair, fettucine and the like) mixed with chunky sauces result in the chunks settling to the bottom. For pastas with chunks try something with a bit more width (like shells, rotini, elbows, penne, ziti) the chunks tend to stick with them a bit better. Could you also try to chop your chunks a bit smaller, or into noodle like shapes/strips, if you must have a thinner noodle.

It is also better to toss all your sauce with all the pasta in the pot with a splash of reserved cooking liquid for a good minute this helps develop the starch and makes the sauce and pasta stick together.

I hope that helps!

Dry noodles, thick sauce. For a thinner sauce you wanna use pasta that has crevices, places for the sauce to collect. Also sauteeing the pasta in with the sauce for a few min gets the sauce a little thicker and gets it to stick on the pasta.

Cook the pasta in salted water, for slightly shorter than you normally would. Briefly drain (don't rinse... in the name of all that is holy, NEVER RINSE!!!) the pasta, reserving some of the cooking water, and add it to a sauté pan over medium high heat with the sauce and a ladle or so of the reserved cooking water. Stir/toss until most of the water is absorbed.

The starch loosened through this process will greatly improve the sauce's ability to adhere to the pasta. Adding more liquid to the dish seems in some ways incredibly counter-intuitive, but it totally works. It also gets around the problem of the sauce not being hot enough and cooling the pasta.

Also, carefully consider the size and shape of the pasta that will be used with the sauce. Some pasta, such as shells and orecchiette, are great at binding to big chunks. Other pasta, such as radiatori and rotini can put a serious grab on a sauce with a slightly finer texture. And so forth. Experiment! :)

Numerous Cooks Illustrated recipes have recommended adding about half the sauce to the pasta and mixing well, then plating and pouring the rest over the top. Always works well for me.

I always make my sauce in a large, deep saute pan, rather than a saucepan. When the pasta is cooked and drained I just add it to the saute pan and heat it up for 2-3 minutes while stirring it together. The large, flat surface of the pan allows even incorporation and keeps the pasta from accidentally breaking. It coats the pasta perfectly and the entire dish is hot and ready to eat.

I usually make sauce in one pan and pasta in another. After I drain the cooked pasta, and place it back in the same pan, I will ladle some sauce into it and mix with tongs to coat the pasta with sauce. Then I will dump the pasta coated with sauce into the pan with the remaining sauce. Use tongs to plate and ladle any extra sauce on top.

Similar to a lot of comments here, I toss the pasta along with some pasta water in the sauce in a large saute pan for the last few minutes of cooking (remove from water a couple minutes early and add to sauce). The starches in the water thicken the sauce and cause it to stick to the pasta. I also like to turn off the heat a little early and let it just settle a little in the pan before serving because it allows everything to come together. (obviously, you have to turn the heat off early or you will overcook from carry-over heat)--if you've ever had a bite from the pan after dinner and thought it tasted better than what was on your plate, you'll be with me on this...