HUGE ones that nobody seems to mention.
* Avoid new debt, especially unstructured debt like payday advances and lines of credit. Notes, like mortages and car loans, are sometimes unavoidable.
* If you have debt, put as much into paying it off as you can afford to. This goes double for credit card debt. Paying the minimum is NOT a money-saving idea. You'd be surprised how far even one extra payment per year will go, especially on long-term debt like mortgages.
* When expenses decrease, act as if they haven't. For instance, an accident came off my driving record as of the last insurance term, dropping monthly premiums by $125 (I don't get any special bonus for paying the whole term at once). I however acted like I always did in terms of budgeting, and 5 months later I had $650 I didn't need in my bill-paying account.
* Your day-to-day money situation is a negative-sum game. You pay more for money you borrow than you get for money you lend. That said, you can still reduce the amount of that difference. Minimize both amount and duration of debt, and whatever's left should go into an interest-bearing account. Money in a checking account is losing value at the rate of inflation. Money in a savings account can at least try to keep pace.
* Learn to operate in cash as much as possible. Debit cards are convenient, but also very seductive. If the account tied to that card is not the only account you have, that card will be approved as long as you have available funds SOMEWHERE. Of course, they'll still overdraft you because it wasn't in THAT account. You can't overdraft cash on hand; if you have enough, you have enough. If you don't, you don't. Very simple.
* However, on the opposite spectrum, set up "bill pay" for as many of your recurring payments as you can. DO NOT do automated drafts if you can help it; that puts your creditor in charge of your money. Automated payments on a date YOU schedule, for a set amount YOU know, can help keep you from overdrafting or having to pay late fees and other penalties. That in turn helps your credit history which in turn saves you even more.
* Fixed utility payments may be convenient, but they usually cost extra and they do nothing to reward you for responsible use. Reduce usage and you reduce costs. Overbudget for your electric bill, and on a hotter or colder month when you can't avoid higher electric bills, it will even itself out without paying a premium for the service.
* You really can live with the A/C set to 76 instead of 72 during the summer, and in doing so you will knock a significant amount off of your energy bill. If you aren't going to be there during the day, you can set it even higher. Similarly, closing all blinds/drapes before you leave the house each morning will slow down the rate of warming and lower cooling costs.
* During the winter, the opposite applies. Let the sun in, turn the temperature down, and dress warmly. If you need to warm up, heating a cup of cocoa or tea in the microwave once a day every day uses about .65kW/h per month (that's a 600-watt oven run for one minute per day), significantly less than having the thermostat set at 74 instead of 68.
* If you live alone, cooking actually may not be cheaper than ordering in, depending on what you cook and what you order. It takes extra time, the raw ingredients cost more for you to buy than it costs the restaurant, it increases energy bills, especially the electric stove/oven (a SERIOUS energy hog; restaurants do everything they can in regards to per-meal energy efficiency), and if you cook extra and never get around to eating the leftovers, not only have you cut the savings for one meal in half but you have to buy food for the second meal twice. If you do cook just for you, do not buy perishables in bulk (you won't use them fast enough to be worth it), always save the leftovers, and remember to use them. All that said, brown-bagging lunch will save you money every time, and is a great use of leftovers if your workplace has a microwave.
* Hibernate your home computer when not using it; don't just put it in sleep mode. Sleep mode on most computers keeps the power source active (many power sources draw their rated wattage no matter how much they're actually using) and keeps sending power to various peripherals like RAM, the CPU, and the network card in order for the computer to be able to wake itself. Hibernation means the computer basically saves its state to hard disk and shuts down, which uses almost no power.
* NEVER leave your amp, stereo system, or other sound equipment on when not using it. Amplification equipment is the absolute biggest watt hog in your house. Why? Because it always, ALWAYS, draws its rated INPUT wattage when it's on, no matter if it's being played or what its volume is set at. The power not being used is wasted by running it through an attenuator (resistor) that converts it to heat, very inefficiently. You may think "oh, it's only a 300-watt amp". Think again. Your average 300w stack actually draws between 600 and 800w from the wall (laws of thermodynamics and all that; no system is 100% efficient and amplification systems are relatively inefficient). Leave it on for an hour when not using it and you might as well take a dollar from your wallet and put it in the electric bill fund.
* During the summer, avoid using your stove/oven. Not only does that tack on additional energy usage by itself, but it warms your home forcing your AC to work longer, compounding the added cost. Look for cold recipes as much as possible; various salads, sandwiches, etc.
As far as being conservative to the point of being cheap:
* Take advantage of every free food opportunity presented to you. Raid the fridge at your church. if you get coupons for free food, buy the absolute minimum required to get the deal.
* If a Ziplock bag was used for something like a sandwich, you can save it and use it again. In the extreme, they can be run through the dishwasher.
* Yes, it's true, you can cook food in the dishwasher. Works best with fish or veggies.