I might as well take a stab at this since I’ve done entirely too much research on various national health care systems.
Financial incentives and disincentives seems to be the way most do it - aimed at providers and patients.
Provider financial incentives are straightforward. Bonuses for coordinated care, efficient health outcomes, nurse/doctor ratios, following recommended treatment protocols, etc. are used all over the place.
Provider financial disincentives seem to be less frequently used, but it is basically the same as above but inverted.
Patient financial incentives don’t seem to be in use much, but France, for instance, provides financial incentives to assign a primary care physician.
Patient financial disincentives are easier with coinsurance since one can simply charge a patient more based on cost/benefit to steer them. Without it though, well, the only other option I can think of is simply not covering ineffective treatments and allowing them to pay for it as an elective if they choose.
Canada for instance, uses private health insurance for vision and dental care, prescription drugs, rehabilitation services, home care, and private rooms in hospitals.
Australia’s private insurance offers more choice of providers (particularly in hospitals), faster access for nonemergency services, and rebates for selected services.
France’s private insurance covers copayments (or co-insurance) and actually helps get private insurers to push the government to negotiate lower reimbursement rates.