The Electrophorus (glorious name, don't you think?) is the most elementary apparatus which uses electrostatic induction to charge things up. You start with a insulating plate on the bottom and you transfer charges (say +) onto it by rubbing with cloth, fur etc.. The second part of the device is a metal plate (often a baking tin on a polythene handle). You lower the plate onto the charged surface and that polarises it. The insulator attracts - charges and repels + charges as far away as they can go on the metal plate. You touch the metal and the + charges all flow through you to ground. You take your finger away and the metal plate is left with an excess of - charges.
An electroscope will show the metal plate is charged and sometimes you can get a small spark off it if you discharge it. You repeat the action :polarise ... dump + charges... remove - charged plate etc. etc. The charges on the plastic plate are not affected (it's an insulator) and you have an endless supply of charges. The energy comes from your muscles. Read the wiki link.
There are many alternative setups for this but a large area between charged plate and metal plate and a very small gap gives best results.
There are a number of pieces of apparatus that use induction to build up very high potentials. Look up Whimshurst Machine, which can be used to charge up two Leyden Jars (capacitors) with enough charge to give a nasty shock.