The articles all seem to point to my mind to the fact that belief in angels depends very much on how you define the idea of an angel. If you see an angel as a spirit who has passed over then yes, I suppose I do work with angels and so do most witches. Again if your definition of angel agrees with the Wikipedia that they are a: "supernatural being depicted in humanoid form" then yes such a definition could fit with most witches. If you consider an angel to be a deceased family member then again, many many witches work with their departed ancestors. If however you define angel (as I do) as a specific messenger of a monothestic deity then it is unlikely such a concept would be embraced by those following the craft. It is important to note once again that witchcraft is a secular craft and not a religion so it is not impossible that a belief in angels and witchcraft could be harmonised. However I'm going to stick my neck out and tell you that you won't find such a belief in most Trad casters.
Wiccan Moonsong Angels, Archangels and Ascended Masters
Cyber Witchcraft Angels in Wicca
Pagan Space Angels - can Wiccans believe
Witches Lore - The Angelic Presence
Witchvox - Earth Angels
I've added an article on Christian Witchcraft as well in case it interests you.
Witchvox - Christian Witchcraft
I'm sorry I can't be a bit more specific about how I would personally go about incorporating a belief in angels into my own path but its just so far away from what I actually do that I can't see how the two could work together.
Image http://www.deviantart.com/art/Angel-in-garden-144395998 (fantasy fairy angel)