Here's a lanyard that I made my dad for Father's Day.
I've seen some really nice ones online, like these and some others here, which are very impressive. I made a simpler version, so I wouldn't get in over my head and tangled up. It still took me a few hours to finish it.
For the completed lanyard, I used a 3-peg knitting spool, Solomon Bar/Portuguese sinnet, weaving with two warps/racking seizing, snake knot, and three different Turk's Head knots.
Attached is a Rough Rider rigging knife, which is not bad at all for what it cost, although the 'locking' marlinspike doesn't stay locked as it should, so be aware of that if you actually intend to use it with knot work instead of as a 'letter opener'.
I've seen and handled different models of rigging knives and some have locking spikes, others do not, so you have to take care to make sure it doesn't close up on your hand when working with them to tighten/loosen knots. Schrade, Camillus, Buck, and Case, are just a few that have made the same type knife in the past in the states, and older used models are hard to find and cost considerably more.
I've had several folks ask me about the 'weaving with two warps/racking seizing' section, so I've added a couple of photos showing the process loose and tightened.