Other than that, if you look under the vehicle at the bump stops and see if they are in regular contact as that would indicate if new springs may help if old ones a bit tired.
My other suggestion, I don't know what tyres/wheels you have on vehicle, but if you fit higher profile tyres you may gain an inch of height depending on what tyres you have fitted, I understand original was 185/65R15 ? It may be possible to fit may be 195/70/15 or even a 16 inch wheel to give more options.
Note this will affect speedo readings and possibly require notifying your insurance company.
There are websites that give wheel/tyre options and how they affect different aspects.
Another cheap option is rubber coil spring assisters for coil springs as below. many years ago I used them with success on a ex taxi Ford Mondeo with 200k miles.