Assuming you have to close the distance and cannot just out range:

Extremely sloped armor can help tremendously by spreading the effective spot size. Add cooling and you can get closer. If the laser wavelength is extremely short, however, this becomes difficult as hard enough x-rays require grazing incidences. Also, if your very sloped armor is a cone, you can rotate to make it a lot easier to spread the heat out. This also only works against an individual laser source, or a very tight cluster.

Damage the laser's optics if possible. A rain of sand from missiles, mass driver launched canisters or Macrons from electrostatic accelerators can damage mirrors and lenses.

Damage the radiators of whatever is shooting the laser at you assuming they're not buried on the surface of a celestial body. Lasers and their power sources require cooling that should be a very easy to spot target.

Assuming you have to close the distance and cannot just out range:

Extremely sloped armor can help tremendously by spreading the effective spot size. Add cooling and you can get closer. If the laser wavelength is extremely short, however, this becomes difficult as hard enough x-rays require grazing incidences. Also, if your very sloped armor is a cone, you can rotate to make it a lot easier to spread the heat out. This also only works against an individual laser source, or a very tight cluster.

Damage the laser's optics if possible. A rain of sand from missiles, mass driver launched canisters or Macrons from electrostatic accelerators can damage mirrors and lenses.

Damage the radiators of whatever is shooting the laser at you assuming they're not buried on the surface of a celestial body. Lasers and their power sources require cooling that should be a very easy to spot and target.