Just start! ...zap bits on as you feel and see what happens. You never know what you're capable of 'till you have a go. If you end up binning it so what ...have another go!
The best way to do it is a have a go.
I was planning on making scrap metal sculptures; as it is I rarely use any recyced materials. One thing is you need a vast amount of junk and I imagine it would need to be carefully sorted to be accesible