Here are two different watch bands I've now made out of paracord, along with a paracord bracelet I made a while back. Both watchbands contain 10-12 feet of paracord.
The one on the right, I did twice this weekend, since no sooner than I finished it, I managed to break the buckle, so I got to redo it. This one is one continuous piece of cord and is woven from one side to the other. This pattern is a little more complex and takes longer to work the cord into the correct position as you work through it.
The center one is two pieces, on for each side of the band and uses a simple crossover and tie from each side.
The biggest challenge for both of these was getting them to the correct length. I finally took my watch and old band, measured the total length and the length from the top to the watch. I then used those measurements, along with a little extra for thickness to set the initial lenght. Both were a little stiff when first completed, but softend up after wearing them a couple of days.
These are fun to make and I'm looking for different patterns to use and also for a pattern to make a belt.