I made a FBCT for a cake I'm doing tomorrow. I peeled off the wax paper without problem, but the frosting has lines in it from where I piped it on. In other words, instead of a smooth look, it looks like lines of frosting going across the image. Will I be able to smooth it out when I transfer it to the cake and it thaws a bit? How do I avoid this problem in the first place?
SOme people do wait until after it is put on the cake and thawed and then use Viva to smooth out the lines. THis is what I like to do: I outline in a medium or stiff and icing to fill should be fairly thin, but not a flow consistency. I also use clear celophane (instead of wax paper) and plexiglass so that after I outline, I can remove the image and then do my fill-in and see what I am doing (lifting the image above my head a bit to see if I have squiggles--don't flip it over--the icing will fall! 
) If there are squiggles or airbubbles, I take a toothpick and swirl it around in the icing until they go away. Someone has also suggested using a paintbrush and that works great too.
Frozen Butter Cream Transfer. Here's the tute link, courtesy of member cali4dawn:
http://www.cakecentral.com/article12-How-To-Create-a-Frozen-Buttercream-Transfer.html
Theresa 
A Frozen Buttercream Transfer...
I think you will find this link helpful....
http://www.cakecentral.com/cake-decorating-ftopict-2926.html
I'm glad to finally know what FBCT finally is! This is the coolest thing ever! I can't wait to try it. Are there any major does or don'ts that y'all have encountered? I have two big cakes this week, but would like to try it next week for my MIL's Bday.
I like to thin out the icing a bit - I get fewer "worms" that way. One tip I got was to let it crust a bit, then use cornstarch on my finger to mush it down a to try and eliminate any squiggles. Also, for the last layer, use the same color icing as your base icing on your cake, and do your best to make that layer smooth and even - it matters because it needs to rest flat and even on your cake! i didn't really think about that my first time, and it was a bit uneven, and as it defrosted, by FBCT warped. Also, do your best to make the edges smooth and even, too - it makes it easier when you put whatever decorative border around the transfer (if you need/want one at all). Some people suggest using those clear plastic covers (like report covers) so you can look underneath and see your work. It sounds like a great idea, but I've only ever used wax paper, though. It is a really cool idea, and it works well.
I did my first fbct last week and really loved it (its the bratz picture in my photos) I also used the plexiglass which I bought at home depot in the replacement windows section, and clear cellophane which enabled me to see the transfer as I worked on it. I also used the Wilton class buttercream icing recipe w/all shortening, which I really liked because it was easy to work with and didn't run at all after thawing. I was nervous about trying it at first but I really liked the result (considering that the bratz cupcake cake was for my supervisor's daughter!!). I can't wait to do another one!
I just did my 2nd fbct last weekend and was very pleased (thrilled) with the results! 
I used wax paper too but greased it a little before icing for easy removal later on. Make sure you freeze it well before transferring or parts will stick 
Now that I've done these, I wonder whatever scared me about them before - will def do this again with the plexiglass as Missyek suggested 
Quote by @%username% on %date%
%body%