I suppose paying yourself first and hiding part of your income (in the form of savings/investments) encourages frugality but I don't think I'd call it a strategy for frugality itself....here's how I'd approach the question. Disclaimer: some of these are things that work *when I do them* but sometimes I slip up. Almost like I'm human or something.
1) Going to stores as little as possible (mostly going to grocery stores and wherever toilet paper and toothpaste come from). They're designed to sell you stuff! Even if you don't buy it right there, it puts the thought in your head. Whether your temptation is clothes or electronics or hardware...don't go near it!
1b.) Avoid advertising (I've actually been terrible about this lately...and I've suffered more temptation than I needed!)
---> This worked well for me for *months* and then the holidays ruined it :(
1c.) (Mostly for...anyone who enjoys this) If you feel the urge to go clothes-shopping...do laundry instead. Makes you realize how much you have, and brings your faves back into the rotation...
2) Procrastinating on purchases. Ok, you've decided you need [thing] but maybe put off going and shopping for it for a week because you don't have time, you're tired, you need to cook/clean/read tonight, etc. Whatever excuse you'd use for an undesirable task.
--->This is kind of at odds with my realization that if I want to have clothes/things I genuinely like, I need to shop for them *before* I am desperate, when I tend to just grab the first thing that kind of maybe works for the purpose (e.g. finding pants that fit *awesome* vs pants that kinda fit).
---> However, having a period of "I want to buy X but I don't need it right NOW" gives you a chance to find it used...
3) If friends ask to hang out, invite them over (or suggest hiking, volleyball, etc) before they get a chance to suggest bar, movie, etc. (Kudos if you have non-spendy friends, but it's a problem for many).
4) Pack lunch in the evening so you don't have the excuse of being "in a rush" in the morning.
---> One of the strategies I suck at. But I know it helps when I use it!
4b) Keep "desk food". Also *use* it. A $3 shelf-stable microwaveable pasta entree is cheaper than takeout. And less attractive than leftovers. Beverages and snacks might reduce "coffee run" temptations if that's a problem.
5) Live in the smallest amount/quality of housing that will keep you sane. Particularly if you rent. Particularly in a HCOLA. I feel like if you let yourself justify it, it can be so easy to blow a few hundred every month on this. (I do think it also applies to houses but I realize there's a lot more "telling the future" involved with buying a house, issue of resale value, etc.) Advantages: less cleaning, less space tempting stuff to accumulate, less heating/utilities used.
All I got for now.
Spouse and I go 3 places during Monday through Friday: work, home & daycare. Saturday, we go to the grocery store for our weekly shopping with a list, then I take kid to the library (when it's cold) I the playground near our house (if it's above freezing)I, and spouse gets an afternoon off to play video games at home. Sunday, we stay home & prep work lunches for the week, and spouse takes the kid out again to the library or playground while I do an afternoon of work prep & get Sunday dinner ready.
We have a schedule for spending money each week, too:
Monday morning, we pay daycare our $125/week for full-time care Monday through Friday, $65 per week for 3 days a week. We divide it up between full time and part time. This cost goes to zero per week for the 12 weeks of the year that I am off full time work (I'm a teacher, so it's typically mid May to early August).
Tuesday through Friday, we usually don't spend any money unless it's a medical emergency or an online bill payment that we've automated & set up on our credit card.
Saturday, we spend around $65-$100 at the grocery store, depending on what we need for meals. Library and playground are free.
Sunday, usually this is the day where we spend a total of $50 per month (divided up to roughly $12.50 per week on Sunday) on either gifts gathered or made throughout the year ($25 per month), or travel plans ($25 per month, almost always involving traveling to see family and involving tent camping in the summer). We pre-buy our gifts & purchase gift cards/online supplies for our travels.
The strategies that we use are automated/scheduled spending, automated bill payment, going to relatively few places & finding free or low cost alternatives for what we do enjoy (for spouse, it's video games that he's owned for 5 years with no recurring charges, for kid & me, it's books and movies from the library).