Everyone should be a shadchan – how to set up a shidduch

Should each of us be setting up Shidduchim?
What are the biggest challenges and difficulties?
Is the “shadchanus” fee only paid to a professional Shadchan, or even to beginners?
What does the Shadchan need to do to earn the fee?
Can you set up two non-observant Jews? One frum and one not frum? Two non-Jews?
What advice do professional Shadchanim have for amateurs?