Yeah honestly I am losing hope for Caltech. There are probably dozens of 4.0s with master's degrees lining up to compete for that spot. My 2 cents on grad school application is probably plan early. Make plans for the four years, including classes and researches. Make sure work loads are evened out over the semesters, start looking for research early and make intermediate goals to achieve. Also make plans for each semesters, look ahead and start working on homeworks as soon as they are made availiable, so that you can move things around more easily.
Then with those guides all you need to do is put in the work, and hope for the best!