Here are some quick tips:-

Use luke warm water when washing. The hotter the water, the quicker the fade.

Limit and lower the temperature of heated tools.

Use heat protection every time.

Use soft circular motions when shampooing to prevent early breaking down of colour molecules.

Use the best quality PH balanced shampoo you can afford, and seal once a week with a matching hair masque.

Use all these tips and your coloured hair will last longer.