A big thanks to A Photo Editor for showing my promo kit to all his followers.
This is the kit I sent to interested companies. Cards, button, fold out poster - lots of little things that showcase my work, all wrapped up in a nice metal customized tin. Always give them something to keep. Even if it's just a card. Give them a leave-behind.
If you aren't following A Photo Editor, it is an invaluable resource for photographers. Bookmark the site. Visit often.