Make it a game to never pay list price for anything.
I have a router/WAP here that I bought as "refurbished" direct from Linksys, about half list price IIRC.
I have a "working outdoors" (not fashionable) Cabela down parka that listed for around $400, bought in March a few years ago for $150.
Yesterday I ordered a book from Amazon. "Used, good condition" was about half the price for a new copy. Wherever possible I order from the used book inventory and almost all of them come in like new condition.
On bigger things, CraigsList and Facebook are your friends. A couple of weeks ago I bought a pair of Klipsch "Heritage" speakers for $850; Klipsch is now selling them new for around $3200, a sum which I would never pay. Craigslist and Facebook usually take some patience. I probably spent a couple of months waiting and watching for what I wanted. But it's like hunting --- fun. Prices on eBay are usually high and shipping on bigger items can be a killer, but you can watch there too. Use bid sniping software like EZSniper and never bid until the last 10 seconds of auction.
This is actually practical advice. Making it a game, hunting. I love this comment most out of all of them.
I always look for used - like new on Amazon. Likely someone just decided they didn't need/want something and amazon marks it down.
I also like the idea about whittling down subscription costs.
I don't track meticulously, but I track core expenses and keep a close eye on those.
I tried multiple times to find cheaper auto insurance but so far haven't had any luck. Same with homeowners, even tried doing them separate but nothing beats our combined policy savings.
My ol man takes 'the game' waay too far. He washes those plastic dixie cups, and plasticware to re-use it. I never did get this since he has perfectly good silverware that can be re-used. He still wears his free work shirt and I don't think he's ever bought clothes that I am aware of...mom buys his pants, sister buys his shoes every other Christmas or so (He still has his new pair in a box), I get him hats to wear. He isn't a great tipper, I think he does like 5 or 10% where I usually do 15%. He's used the neighbors recycled oil from their oil changes in his vehicles. He waits till the wires are showing on the cars tires before he deems them ready for replacement. He is insane about his gas usage, runs the house too cold, for too long in the winter...and same with AC, it can be quite warm in his house in the summer. He will water down the juice he buys from the store to get 2 containers out of one. He does this weird thing where he will try and cook with just what he has in the pantry for months on end without going to the grocery store.
I shop at discount stores and buy in bulk. I never pay retail for gas, its either from CostCo or with a coupon, or my grocery has reward or a rewards credit card.
I play the cash back game, but even my ol man is way better than I am at that. Sometimes I prepay utilities if its utilities category to the top of the max cash back reward, or same with groceries I will stock up on things at the end of the cash back cycle.
I use electricity sparingly, unplugging everything that I don't use. I don't know if I totally recommend this but sometimes I go a day without a shower, only on the days that I had like no physical activity. I will re wear a pair of jeans like 2 or 3x before tossing it in the wash as long as they are clean.
I try to buy things that have multiple purposes. I buy my books used like new. My wife is great about finding free books no her kindle. We do pay for amazon prime, and netflix, but our folks split the cost of those memberships with us. We have a family cell plan and Sister in law and parents pay us the monthly fee, so its more reasonable. We don't pay for Uber, for instance we are travelling to San Francisco and again to Vegas, it was over $220 plus tax for airport parking, so I offered to fill my dad's tank if he brought us and picked us up...he was more then willing.
We keep it in the family. A real DIY family that helps eachother out, sort of trading labor and loaning tools/borrowing tools rather than paying for a service call.
I wash my own vehicles as often as possible. DO as much maintenance as it makese senese, changing my own wiper blades, filling fuel, brake jobs and any small easy repairs like alternator and battery swaps. I shop around for tires.
I return things when I get buyers remorse. It happens. I return things I don't use rather than letting them sit on a random shelf or tossing them into a box in a corner. I sell what I haven't used in a while on Facebook. Dropping the price until someone bites. I buy used stuff off fb marketplace.
I keep things in my amazon cart and watch for price change notifications. I avoid impulse purchases.
I avoid fee's and interest like my life depends on it.