Assume for the moment a '30s variety Depression lies just ahead. Here are a few things you may wish to consider.
Nothing lasts forever. You'll be living among the newly poor and they will be unpredictable, even dangerous, but it's out of confusion and desperation. Remember, your friends and neighbors actually are blameless for what has befallen them, aside from being unprepared, and they'll still be around when the hard times have passed. For your part, you don't have to be a self-sacrificing martyr but you do have to acquit yourself honorably. There will come a time when you'll have to answer for what you did and didn't do. You'll want to look back and know you did the best you could with what you had.
Get out of debt. What you actually own may be all you actually have. You'll be sacrificing for the present, not the future. You can't do either if you're sacrificing for the past. Debts that are manageable now will crush you in a Depression, pay off those loans. If you must have credit cards, treat them like a thirty day interest-free loan and carry a zero balance. Own at least one vehicle outright, preferably a plain, utilitarian, economical model of good quality, well maintained. If you're a city person or an apartment dweller, consider getting a habitable RV-style vehicle and a well situated parcel of land as well. After you've attended to the basics, insulate yourself from currency disruptions with cold hard cash, meaning precious metals. For most of us that means silver.
Save. Live within your means. Have a savings account and an adequate checking account, yes, at a bank, if the banks collapse money will be the least of your problems. In some phase cash will be king, keep a few hundred dollars in small denominations squirreled away. You might put aside trading material too: liquor, ammunition, medical supplies, tobacco, that sort of thing.
Stock up. Don't buy groceries, lay in supplies. Better yet, hoard. Look at it this way, if it comes to where food is more valuable than gold it's better to have the food in the first place. Keep a perpetual three to six month's supply of long shelf-life staples, even hard times have their hard times. Next time you're shopping, look around. How many light bulbs do you have? Durable clothing? Tough and comfortable shoes? Consider what you might need when you're down with the flu and threatened by roaming gangs or looters or partisan raids. And whatever you buy, buy quality. Reliability is more valuable than features. Experienced engineers adore robust simplicity, you should too.
Learn the basics. Carpentry, vegetable gardening, emergency medical skills, that sort of thing. You don't have to be a back-to-the-land fanatic or do your own dentistry, but you do need to be minimally competent and self-reliant. If you can set up a surround-sound system you can replace a light switch. Equip yourself with excellent hand tools and basic components. Most of what you'll be doing will be maintenance. What you don't know your friends and neighbors will. Learn from each other, widen your skills, become more valuable to yourself and others.
Arm yourself. There's no need to outfit yourself like a comic book commando. A .22 rimfire rifle and a shotgun will do nicely for taking game and protecting home and family from casual intruders. For those special occasions, add a center-fire rifle, capable but mild enough for your smaller adults to handle with confidence. There won't actually be much call for shooting through engine blocks half a county away. Handguns are a weapon of last resort, if a bad guy gets within whispering range your fitness to survive is questionable on other grounds. Plain vanilla is preferable to high-tech. Figure five tough years and think about how much ammunition you might need, worst case, then triple it.
Anticipate trouble. Expect bizarre and violent behavior at the outset from the kind of people who take gravity personally. They're not the real threat however, the improvident and irrational will expend themselves early on, it's the mid and later phases that bring out the really dangerous sorts. A Depression is the sort of change that favors competent gangs, urban demagogues and rural populists, and semi-official committees of this and that, usually more or less lawless and eager to back up intimidation with force. Your mother's advice is the best, be seen as no better off than your neighbors whether you are or not, be polite to strangers but don't trust them, stay away from crowds, fasten on fundamentals like a puppy to a root.
Know yourself. A Depression not only throws people back on their own resources, it demands good judgment in times of uncertainty and stress. The last few decades were about choosing between good and bad, in hard times your decisions will be between bad and worse. Yet even when your choices are bad, and they will be, there will always be an even worse choice. Know what you will compromise and what you will not compromise—ever.
Amusement. Although 'thirties-era people had unforgettable tales of misfortune, it's remarkable that most also remembered those times with fondness. The gentle delights of ordinary life provided most of their entertainment. Notice how valuable their diaries and recollections and ephemera have become. Notice how their recollections centered on small things, anecdotes of how they "made do" when their life was stripped of artifice except for pretending on Saturday nights they were doing well when everybody knew better. It was an era when style was in style, probably the last time the affluent, street thugs and destitute men in soup lines all wore three-piece suits.
Final thoughts. Every era has its texture, every texture has its fine grain. For the 'thirties it was G-Men and Public Enemies, the Okies and the Dustbowl, union organizers and union busters, Huey Long and Father Coughlin, the National Recovery Act. These things affected relatively few people directly, most felt far more involved than they really were. One doesn't lose much by giving only passing attention to such things, nor is there much to be gained. It's wisest to treat politics and mass movements like supermarket music, unrewarding yet not quite avoidable. As a general rule, if there's nothing in it for you by that same afternoon, make your excuses.