Any particular way to make this?
It seems everybody suggests doing this but, nobody knows how to really make it.
Are there any step-by-step instructions for this or just examples?
Making your own 2.4GHz oscillator is rather like do-it-yourself home surgery. Seems simple in concept, but rather difficult in practice. It's not for the novice.
Why would you combine oscillators? It is dead easy to buy a 2.4GHz oscillator. What form do you need? An IC, a module, a circuit board, a rack mount box, or something else? What stability and phase noise performance do you want?