Next time you are the the hardware store, grab a coil of cheap manila. Then whenever you are hanging out with the wife watching tv or something like that, just practice them and cut them off when you are done with it. I bet you will be able to do it in your sleep before you get 15' in. The nice thing with cheap manila is that it's not hard lay and it holds its shape, so you don't need tools or have it unlay (hair gel works when you get to that). Start with the back splice, then eye splice, then the manrope knot (handy on the end of a lanyard or similar). Then start messing around with the chain splice, which is used for splicing on a ring or snap, and then the right angle splice so you can do a proper cargo net lol. Just like knots, after a bit it becomes fun. Tenex or other hollow braids are even easier, so you can make stuff with that too. By then once you try double braids it isn't that hard, just more measuring and on tight ones like blaze more milking it smooth and setting it with a hammer