There really is not much difference between a fob, lanyard or plain old key chain. It simply depends on how you use them or what size you make the loop. You can look in my archives to see other examples of these but here are the latest ones I have made for my customers.
Below in yellow and green are the high school colors of a friend of mine. (School colors are a popular theme with my customers). This "key chain" was done with a square sinnet that blends to a round/crown sinnet and then back to square with a pewter skull bead at the top.
This one is called a rattle snake knot for obvious reasons.
These are just basic square sinnets finished by a lanyard knot.