Storm shelter
A storm shelter is a place where colonists can take refuge from a solar flare. The main settlement will be well shielded, so it in itself will be a storm shelter. However, manned rovers, railroad cars, airships and landers will need emergency shielding if a solar flare occurs.
Early warning
Early warning satellites are in place for the Earth, as a strong solar storm can be damaging to the technological and power infrastructure. These would also be used to warn Mars of a solar storm.[1]
Physical Shields
A good material for this is polyethylene, because it contains many hydrogen atoms, is light and can be made on Mars easily. Water, which is two-thirds hydrogen, is another shielding option. Rock, regolith and concrete are all options if the equipment is available to arrange them in a suitable configuration. A thickness of 5 meters is more than adequate.
Energy Shields
Strong localized magnetic fields have been shown to offer significant shielding from radiation. Such shields could be made portable for use on vehicles.
