How to find n-sheeted covering space of a topological space explicitly(If exists)?

Question

We know that there is a one to one Galois correspondence between subgroups of the fundamental group of some topological space and covering space for a path connected and locally path connected topological space.suppose n-sheeted covering space exist for some topological space X.So if I want to construct n-sheeted covering space explicitly then what is the general way to find that?