How to drain zucchini and eggplant I am making a dish that involves roasted vegetables and couscous. I have often found, though, that the zucchini and eggplant are unpalatably watery after roasting them. I have read that if you salt and/or press zucchini and eggplant, you can reduce the amount of water left in them and give them a better texture when cooked. What is the best procedure to rid the zucchini and eggplant of their water before roasting them?

Update:

I sliced the zucchini and eggplant and placed them on a baking sheet, filling one layer of a large sheet. I salted them with about 1/4 cup kosher salt. Then I placed a cutting board that just fit inside the edges over the sheet and put my stand mixer on top. I let it sit for 20 minutes, then wiped off all the salt and water that had drained out. This resulted in a much better product.

However, I don't really know if I used a good amount of salt (too much? too little?) and if I left them to drain for a good length of time (too long? too short?) to get the best results. It worked pretty well—not too salty, veggie texture nice and chewy—but could I get even better results by using a more precise procedure?
I think your problem will disappear with proper technique. Zucchini and eggplant are indeed full of water.  You have to both salt them well, to draw out the water, and cook them long enough for the liquid to evaporate.  

It sounds like you are both under-salting and under-cooking.  Try roasting for longer and/or at a higher temperature.  My personal favorite way to do them is on the grill, where the direct heat and lack of a 'pan' allows lots of evaporation and also delicious browning.