Hi Stephen,
A soundtrack is like a salad (final mix).
You choose the ingredients (individual SFX, dialogue tracks, music stems, etc.) that you want to put in that salad.
The salad quality and it's taste (how it sounds) is dependent on the ingredients you put in it,
For example, if you go to the store and buy GMO (genetically modified organisms) tomatoes, under-ripened pears or out-of-season pears, lettuce that's been mass produced, etc., your salad isn't going to taste very good. (read: if you use wonky mass-produced library sound effects that are over-compressed, up/down-converted, processed, harsh, and horrible-sounding [Disclaimer: don't get me wrong - there are many sound effects libraries you can buy that are boutique and sound amazing and are tailored that way for high fidelity and truer sound, and are provided as an alternative to the larger, more bland and "commercial" libraries you buy out there, e.g. "KEWL HOLLYWOOD FX 500000000000".])
If you use your own home-grown ingredients from your backyard like fresh vegetables picked off the plant, fresh organic tomatoes and lettuce, etc. (SFX that you yourself record at the proper sample rate and miced properly with high quality equipment), the end product is going to be a very nice tasting salad (nice-sounding final mix).
The way to get a good, full sounding soundtrack is to use the full spectrum wisely. Don't put 12 low-end rumbles and whooshes in there all piled up on each-other. Spread your sounds around the spectrum wisely. I think expert choice and management of your tracks is important to keep in mind while putting together the soundtrack. If done correctly, the mixer has an easy job putting emphasis on certain things and really creating an organic track that captivates the listener and puts him in a 360 degree environment that sounds real and convincing. Otherwise, if something is out of place or it's messy in the lows or highs or mids, it just doesn't have the same impact. It doesn't take a lot of experience to achieve this, I don't think. It's just building it correctly in the first place so you don't have to spend a bunch of time processing things and mucking it up later.
One thing I noticed while watching that cinematic you linked, is that the mixer made "space" for everything. I.e., there wasn't 20 things all playing at once, but rather, he played up specific sounds here and there and made sure the mast crack and crash wasn't on the dialogue (which is also important to get coordinated with the video editor so you make yourself space for that type of thing). Just an observation..