I suppose it really depends on the Mormon, just as with any other Christian.
There are varying opinions about caffiene in the form of soft drinks and other caffienated beverages that are not coffee and tea (specifically soft drinks and energy drinks). Some believe that ANY carbonated beverage should not be drunk. Some believe that any CAFFIENATED carbonated beverage should not be drunk. Others feel that any beverage is fine other than any form of alcohol, coffee and tea. While it's true that in a 60 minutes interview, then President of the Church Gordon B. Hinckley basically answered that we do not drink caffiene, some see that as a personal opinion since he was not "behind the pulpit" so to speak, while others see him making an official statement because he was speaking and being interviewed as President of the Church, not as Gordon Hinckley. Some even have personal opinions that diet or caffiene free sodas are fine, but the more caffiene a soda has the worse it is for you.
Movie ratings: We have been counseled to not watch rated R movies. This counsel, I believe, was given prior to the creation of a PG-13 rating. So, some will watch PG-13, some will not. I personally am very leary of PG-13 rated movies as most of them these days are just a hairs breath away from an R rating. But that isn't to say that I don't watch some PG-13 movies. But I do prefer to stick to the PG and G movies. My opion is that any really good movie is just as good without all the cussing, and sex, and about 85% of the violence. It's a personal preference.
Generally speaking a list of Do's and Don't's related to health issues can be found here, http://scriptures.lds.org/en/dc/89 although the list is not all inclusive, in the recent past it has been said that many of the things of our modern day were not created when the Word of Wisdom (as it has become known) was revealed, so the general course of action is to be aware of what you eat and what is harmful to you and what can be acceptable by using some common sense and moderation in all things.
Also, generally speaking, we don't cuss, or wear overly revealing clothing. We do pray (probably several times a day individually as well as with our families) to our Heavenly Father (aka God, the Father) in the name of Jesus Christ. We strive to be honest in our dealings with our fellow man. We are very family oriented, prefering to do things with family if a choice is required (many times, but not ALL the time). We are friendly with our neighbors, co-workers, fellow students, and society in general. While missionary work is on our minds (some more than others) we do think about things other than missionary work, and we do not become friends with someone JUST in an effort to convert them.
I guess you could also say in all honesty that we strive to do right, and sometimes that means that we don't do some of the things that modern society has deemed acceptable. We have our values, our morals, our standards and we strive daily to live by those things.
And please, don't misunderstand. We all (those in and out of the church) have our free will to do or not do as we choose. The prophets have given us guidlines and principles over time which have been given to us, we believe, by God, for our benefit when we see fit to live them. For all of us, there are things we struggle with in our day to day living which contradicts what we have been told and given to do. But that's not a Mormon thing, that a human race thing. We all know what to do in a given situation, but sometimes we just don't do it. That's what makes us human. For example, we all know that eating fried foods is not the healthiest thing in the world, but many of us (especially in the US) still eat it.