Pippin,
I have some meditations that I do, but they were supplied to me by a psychic friend, rather than from Theosophy. There are a few things in Theosophical literature about meditating. Let me dig around and see what I can find.
For more on meditating, there is a lot on the Buddhist Forum on meditating:
http://www.lioncity.net/buddhism/index.php?showforum=8Take a look and see if you find something there that works for you. You also may want to join the Buddhist Forum just for the fun of it. I use the usernname Skywalker there, and I post there almost everyday.