Here's an example of my traditional multi media convention badges.

They're generally 3"x4" and no larger than 5"x6". They come laminated and slot hole punched, ready to wear!

I use a variety of mediums, including:
Prisma pencils, Faber Castell Polychromos pencils, Prisma markers, Faber Castell markers, Tombow markers, Sai Watercolor markers, Zig clean color markers, Sakura gel pens, Pigma inks, Kuratake inks, acrylic paint, and a variety of papers including toned, recycled and scrapbook papers.

I generally only take commissions during conventions, but occasionally I do offer them online via my Twitter / Weasyl or fA journal!