I am no expert, in fact I am a theorist mostly, but here goes:
Keep it as simple and diversified as you can and you can't go wrong. It is called a diverified portfolio for a reason. You do not want to invest in only one stock. You also do not want to put all your worth in one form. Invest in some things that have inherent value such as gold, silver, and platinum. Keep these things on-hand in a safe place, and a secret. The values of things that change independently of each other can be a great asset. Eliminate the middle man whenever possible. Why pay commission to a broker when you don't need a degree to broker? Buy when values (demand) are low and sell when values (demand) are high. Keep it as tangible or as liquid as you can. Maybe these are two different things, I'm not sure. An off-shore account in a powerful, neutral country might be a good idea in case TSHTF here in the US and the banks get commandeered or whatever it's called. I don't know.
In order to reap dividends, you must have some money invested in stock. Also, for local barter if the economy gets killed, you should have a supply of surplus consumables with as indefinite a shelf-life as possible, such as canned goods and ammunition. If you value it, so too will others. If others value it, so should you, and so have some to trade.
Another economic safegaurd to have, probably the most important one of all, is a basic, marketable skill that most people in today's world take for granted to the point that they would always rather pay for it, such as mechanic, electrician, and even gardener.