My wife and I follow Dave Ramsey's style of money management and are very secure in doing so over the years. We have a nice amount saved up, a great budget which allows us to live comfortably, yet save a lot of money towards our future. That said, I'm not banking on the military retirement should the benefits not be there, or should I choose to separate before 20.
Rental houses can be a tricky investment, as well as prescious metals. I don't do either of those because I have seen relatives and my current landlord handle multiple houses and have no time off. The possibility of having terrible tenants rent your place is high, and you will likely have a lot of work to do on your weekends. A solution to managing it yourself would be to have a company do that for you. It's not to say you cannot make some extra money, but it's not for me.
One of the other things we do is open up money market accounts to save larger amounts of money towards our emergency fund, car fund, and house fund. I'm not planning on buying a house while in the military and just saving money into the house fund. My goal will be to have enough to pay for a a portion or the entire house (~150-200K) after retirement. Following this plan allowed me to pay for a car in cash recently, and it was a great feeling walking away from the dealer owning the car outright with zero debt.
This style is not for everyone, but I like it because it makes my wife feel secure while I am away working, and when we need to make purchases that are large. I'm willing to answer any serious questions, but I'm not a big investment guy other than my IRA and my kids' education funds. I do most of my investing through USAA and they are great. I have also heard wonderful things about Vanguard, and am looking towards moving my Roth IRA in that direction relatively soon.
I laughed at this, but have found this to be very true when talking about investments with friends/family. I never bring up the subject, just like I don't like talking about religion, politics, because it's pointless. However, I don't mind mentioning the Dave Ramsey stuff to others. You'll find that most folks have no savings of any kind, which is pretty scary. There isn't a lot of financial accountability among our populace, much less our government but I don't want to digress.