Hi there. I do. I think there are 3 basic ways in which we promote ourselves and they are all equally important:
1- Have a website to show all your work and contact information.
2- Have your work featured on good and known online portfolio sites like ChildrensIllustrators, PictureBook or Theispot for example.
3- Send out postcards to publishers.
I do all three. I also have an agent and that helps too. Even if the agent promotes your work I believe we still have to be out there and promote as well. Ultimately all my book projects, regardless of where they came from, are handled by my agent of course. But I think is extremly useful to be active promoting ourselves and always try to keep up to date with what is happening out there.
Every artists is different, this is just what I do. I do recommend however that you find ways to be seen. There is way too many talent out there and the competition is tough.
What's the value of an amazing portfolio if Editors or ADs can't see it?