Always read carefully instruction manual of eletric devices you use including all recommendations, setting, instalation to model, safety instructions etc. Motor and speed controller must be placed to model with regards to best possible cooling.
Power cables between motor and controller must be as short as possible, max 150mm. If it is necessary to extend wires, alway extend both wires (plus and minus). For every 200-250mm of extension add lowimpedance capacitor between plus and minus cable. Don't connect controller directly to power supply, always use good accumulators.
Place receiver as far as possible from power system (motor, controller, battery) - minimal distance is 100mm.
Minimal distance between receiver and servos is 50mm.
Antenna must be placed as far as possible from all cables, metal and carbon fibre parts. Antenna with best efficiency is straight antenna placed perpendicularly to rest of cables in model (vertically to the model) leading out of fuselage.
When carbon fibre fuselage is used antenna must be galvanically separated from fuselage.
Consider using speed controllers with BEC for higher power than 1000W. It's recommended to use OPTO controller.
For big glides always use OPTO speed controllers and receiver accus.
Apply only new high quality connectors. Occasionally check connectors and soldered connections.