've gotten a lot of emails asking me how to find people to promote to. I always recommend they get the latest Graphic Designer & Artist Market and Children's Writers and illustrator's Market books. They have a ton of information in there as well as name and addresses of potential clients. Another thing I do is google searches. I use phrases like “illustrator submissions” or “looking for an illustrator” (you would obviously use search terms for your creative profession). I also look at the client list from other illustrators. To save yourself some postage, be sure and research the companies you are going to promote to. They may have specific guidelines for what they are looking for or their products may not fit your style. Don't just send your promotions blindly, know who you are sending to.