Isolate the area with the fault - 

If a specific fuse, MCB or RCBO keeps tripping unplug all appliances on that circuit. Reset the protective device and if you no longer experience the issue its likely one of the appliances is at fault. By re plugging in each device one by one you can determine which is at fault.
 

Overloaded Circuits - 

Overloaded plug sockets and circuits are one of the top reasons for overheating and protective devices like an MCB or RCBO tripping. The use of unfused extension leads and overloaded socket outlets can create overheating to both the accessory and circuit. Re distributing appliances and accessories reduces the chances of overheating and spreads the current being drawn across multiple circuits.
 

Inspect plugs, cables and accessories - 

By inspecting cables for damage to the insulation or frayed wires you can eliminate the potential for a fault. Rmove and accessory that has visible damage and have it replaced. Damaged cords or accessories with signs of overheating should never be used and replaced immediately.
 

Test with a known working device - 

If you have an outlet that appears to have no power test it with a known working device. If the device doesn't work across multiple outlets there could be a much bigger problem that needs investigating by a professional.
 

Don't Ignore early signs - 

Occasional dimming or buzzing may appear harmless but often hints at a larger underlying issue and can even pose a severe safety risk. Having them checked earlier will reduce the inconvenience, is likely to save you money in the long run and reduce any potential safety risk.