I used to buy those bargain bags of components back when I was a teenager and built up boxes of good stuff and experimented a lot with amps and other circuits. My favourite project was light-beam communications using converted torches and opto sensors (made from standard can transistors with the tops sawn off and filled with liquid plastic to form a lens). My mate and I could get it working across a good sized field. Many of my ideas came from Elektor, ETI and Wireless World.

All that has gone now, disposed of over a series of house moves.