There are many preppers who taking the time to make skill building a priority. The Survival Sherpa is applying his vast knowledge to the field and showing his audience ways to learn skills and be more efficient. Check his site out, it's very informative. The Organic Prepper is turning her back on consumerism and focusing on finding local sources for food to create a food pantry.
There are many things you can learn to promote a more sustainable lifestyle while living in a densely populated area. In fact, 80% of the population lives in an urban environment, so do not let that stop you from your prepping endeavors.