Steve,
Apologies for my spelling error! In regards to workshops and seminars, there have been a number over the last few years here in the states. Planet Figure sponsored one several years ago I was fortunate enough to take with Fernando Ruiz. It's kinda be at the right place at the right time. I have also had the opportunity to be in classes with Penny Meyers, Matt Springer, Doug Cohen, Anders Heinz, Mike Hall, and Bob Langenberg. You will find that many shows have a workshop prior to the show. As David O. pointed out, we are likely to have another workshop at our show in Atlanta next year. Penny Meyers is doing one at MFCA this year on flats and Jason Green is doing one in Tulsa this year, but believe it is already filled. Not sure where you live, but look for a club nearby and one of the major shows (MFCA, Chicago, Atlanta, Tulsa, etc.) for seminars and workshops.
Since you like fantasy pieces, I recommend workshops at Wonderfest, (I've attended several airbrush classes) plus look at shows sponsored by Cool Mini, Reaper, and Adepticon. I've learned from every workshop I've attended and made some great friends, so I highly recommend it! If I can help anymore, please write me.