For the first version, you'll need a bracelet with decent-sized links, the charms of your choice, and jump rings.
I didn't have enough jump rings of a same size, so I took these off of this necklace which I was re-doing anyawy.
Next, take your needle-nose pliers, (I use two sets), twist the jump ring open, loop it through a link in the chain, add the charm, then twist it closed. Be sure to TWIST, not try to pull them open or you'll never get them to go back right and it will look pretty bad.
I find it helpful to count out how far apart I want the charms before I get started so I can be sure they will be evenly spaced and it will be as full as I want it to be when it is done.
...And there's version 1!
For version 2, everything is the same except this time I made the bracelet itself from scratch as well.
I found some old chain I had lying around, trimmed it to the proper length. Then, using jump rings, I attached the toggle clasp to the ends.
Here it is with just the toggle on.
Once I had the clasp done, I began adding charms just like before.