Metal charm bracelets are great presents for friends because the charms will have been individually chosen by you, and so it will be unique. You can really make someone smile with your choice of charms; they can be as personal as you like.
If you buy a plain charm bracelet, you can add as many charms as you want, making it a subtle slender bracelet with a couple of charms, or a bracelet that is full of different charms, making it jangly and more noticeable.
You could always only put a couple of charms on it, allowing your friend to get other ones as s/he sees fit. That way you won’t need to be worried that they may not like it, as it’s up to them what goes on it.
If you wanted to mix it up a bit, you could get a few Swarovski beads or glass beads to go with it, so that the bracelet has a little colour as well as the silver, copper or gold colouring of the charms.
You could choose flowers, fairies and hearts to go on your friend’s bracelet, or be more adventurous with pirate flags, scissors and telephone boxes.
You imagination (and possibly your purse) is your only limit, and you can be sure that your friend will appreciate the effort of you buying him/her a personalised charm bracelet as a gift.