Freezing
The lowest-effort, lowest-risk preserving method for most home gardeners, and the right default for anything you're unsure about.
How it works
Most vegetables need blanching first (a brief plunge in boiling water, then ice water) to stop enzyme activity that would otherwise ruin texture and flavour in the freezer. Fruit generally doesn't need blanching, just wash, prepare, and freeze on a tray before bagging so pieces don't clump.
Safety
Freezing doesn't kill bacteria, it just stops them multiplying, so start with good-quality, clean produce. Label with contents and date, most frozen vegetables hold quality for 8-12 months.
Good crops for this method
TomatoCapsicum & ChilliZucchini & PumpkinGreen BeansPeasSilverbeet & SpinachKaleCarrotBroccoli & CauliflowerCabbageSweet CornBasilCoriander, Parsley & DillStrawberryRhubarbCucumber