I find pencils a very gentle, sensitive medium for portraits. They work particularly well on young faces or where a more informal look is required. They also work well as a collection of small, individual portraits. Choose from a sanguine colour on white or navy and white on a grey paper. If you're looking for a smaller portrait and/or price is an issue, pencil is the one for you.
Here's a collection of pencil portraits - due to their subtly they don't always photograph well but hopefully you can get an idea. Get an idea of what's involved in the commission process and feel free to make an enquiry for a pencil portrait - there's no committment in contacting me and I'd be happy to discuss the options.