How does a person legally “spend down” without gifting?

Depends on how much money they have. Even after prepaying Moms funeral costs she had 20k. I placed her in a LTC facility and she paid privately for 2 months. That gave me time to apply for Medicaid and provide them everything they needed. After proving she was spent down, Medicaid started the 3rd month.

Personal items such as the best walker there is, any other needed equipment, any care needed or wanted medically, future funeral costs if a funeral is wanted, going into care and actually PAYING for that care, then applying with the facility for ongoing help through Medicaid.
Much depends here upon the amounts you are speaking of.
Certainly if you are still driving you can buy yourself a new car.
You can take a lovely vacation and even hire a companion or caregiver.
You can hire in home help.
There are basically a million things you can spend on.
You may keep that new car and your home, and whatever amount is allowed in your own state.

None of the money/assets/property goes to benefit a person other than the applicant. Things need to be sold at fair market value. Don't sign over vehicles, properties/assets, etc. My Mom uses an iPad to play games and such. Only she uses it. I used her money to get her a special mobile phone for people with impairment, and hearing aids. We bought a pre-paid funeral policy for my MIL with her funds and a new tv for her room in the facility. Depending on what state the applicant is in, the financial "look back" back can be 5 years (they don't go back that far unless Medicaid sees a reason to dig).

By putting in place a prepaid funeral and burial, if that’s what’s chosen, buying all clothing, and supplies needed. A lift chair, a rollator, hearing aids, tv with good features for ease with close captioning, a grabber, new glasses, etc. the list can go on and on for things an aging person may need

Buying a handicapped vehicle, stair lift, burial fund, or private pay for in-home care.