Building a simple Natural Radio Receiver is not too difficult for anyone with basic construction skills. Most of these circuits use readily available parts and the layout is not overly critical. Just remember that since these circuits are high-gain and the input impedance is high in the case of E-Field receivers, to keep the input and output sides of the circuitry separated.
Steve McGreevy’s BBB-4 (BBB = Bare Bones Basic) is relatively easy to build and is the product of many years of experimenting and research.
Radio Waves Below 22 Hz
Renato Romero’s site has quite a few diagrams of Natural Radio receiver circuits along with many design ideas.