Mod Note:
Evading customs duty is illegal. Please refrain from discussing the same here.
No parcel sent through postal services / couriers can evade custom deptt.
In fact each and every packet is sent to customs deptt and only after customs releases that packet, Indian post / courier company delivers it.
One of my packets, was even cut open by custom deptt to check if it contained the same mobile phone as declared (I had paid advanced custom duty for that mobile).
Its entirely upto the custom deptt to charge the duty for the content of the parcel or not.
They have complete powers for checking a parcel, increasing/decreasing/exempting the duty and even imposing fines.
If the parcel is routed through official channels, we don't have any method of evading the duty.