1) Home insulation and/or storm windows: 4-10% return, depending on your starting point and level of DIY. Bonus: will lower your expenses in retirement, lowering your FIRE number. Downside: Limited investment size.
2) Home solar panels: I'm buying some of these, and calculated about a >6% ROI
if electricity prices and net metering stay the same. Bonus: will lower your expenses in retirement, lowering your FIRE number. Downside: Limited investment size.
3) TIP or VTIP: Your realized yield on these inflation-protected bond funds is going to be harder to calculate than if you just bought a bond directly from Treasury direct.
4) Ibonds: as mentioned. Downside: Limited investment size, risk of turning into low-yielding treasuries as the stock market takes off.
5) Preferred stocks: These are senior to common stocks in a liquidation, but less protected than bonds. They only get volatile when the SHTF once a decade, and don't stay down for too long. PFF and PGF yield between 4.7% and 5.5%. These tend to be issued by financial companies unless you go with PFXF, which is yielding 5.4% right now. I follow some preferred stocks that yield over 6.5% like Citigroup's J series, Summit Hotels' F series, and several REITs.
6) Deep in-the-money covered calls: For example, buy a stock for $10 and sell a call option against it at the $8 strike price for $2.50. You'll have to sell your stock for $8, but the $2.50 premium more than compensates you because options include a time value premium. Thus your outlay is $10 and your income is $8+$2.50. Plus, you are absolutely immune to any drop in price less than 20% in this example. If the stock did drop 21%, the call option you sold to somebody would be worthless, and you'd only be down 1% instead of 21%. Then you just sell another call. This is a defensive play that attempts to profit from high volatility in the financial markets.
7) Small-cap value and mid-cap value: These sectors have PE ratios in the low teens, which suggests they have minimal downside compared to tech stocks with higher valuations. If inflation is higher than expected, these firms' earnings will be discounted, but less so than for their growth counterparts. E.g. VIOV or VOE.
8) Downsize your car: Extreme example: Sell the 2017 Tahoe and get a 2022 Corolla Hybrid. Even if you have to pay something out-of-pocket to make such a change, you'll be locking in a lower cost of transportation and more inflation resilience for years into the future. If you want to calculate the exact savings that are possible, go to
https://www.edmunds.com/tco.html. Try out different scenarios. There's a good chance that a newer car exists that will have a lower 5-year cost of ownership than your current ride, and this difference will amount to thousands of dollars over time. Even if you already have an economy car, UPGRADING it somehow might make sense in today's insane used car market. While on the subject of Corollas, Edmunds reports that a 2016 model has a several thousand dollar HIGHER cost of ownership over the next 5 years than a brand new 2022 model with the same trim package! The only reason not to make such a change is if you don't have the upfront cash to make the trade, and that's not your problem at the moment.
9) Preventative maintenance: Suppose you have a 10 year old water heater that was installed without a pan under it. You could either replace it now or wait for it to cause water damage when it fails - and also have to replace it. That's an easy choice. Other choices include your house needing a roof, your tires being bald, your house not having a termite policy, getting doctor checkups and regular labs run, obtaining counseling for any emotional / life decision / stress / depression issues, following the maintenance schedule on your car, and having your HVAC system checked and cleaned.
