Thanks everyone who replied to my other post, all good advice! Shirley I used the upside down method, oh I am in love with it! There may be a decent looking cake yet in my future! 
It wasn't perfect but with some practice and better-whipped IMBC, I have a good shot anyway.
Now making the IMBC--the first time I used the whisk the entire time simply because I didn't read through the directions 
but it seemed to be okay. I can't say for sure but I think it was more overbeating or on high speed for too long rather than the whisk (although I'm sure that adds into it). I will switch to the paddle next time--now is it before or after adding the butter? Antonia you said after when you mix it, correct?
I do think I will have better luck using fresh IMBC rather than re-whipped also. How does IMBC hold color? Any problems with spotting or splotches, etc.?
Okay, the problem I did have was the top. I used parchment, I might try the acetate next time. I think the "trenches" were from the parchment but the holes, moon-crater-like, I think were from either overwhipping but actually I am leaning more towards it not being spread and pushed down into the board/paper better. Any advice? Thanks everyone! 
Edited to ask: what about square cakes? I'm sure the top could be done the same but what about crisp edges?
I am seeing a little glare from the foil board so it's a bit difficult to see the sides, but the edges look great. The top crater action probably was from the parchment paper, it absorbs moisture and wrinkles. Could be the icing was overbeaten but I'm not sure. I switch to the paddle beater just as it's time to add the butter. I use the whisk for the egg whites and when beating in the cooked syrup. I also found it's helpful to tape the acetate paper smoothly to a lucite circle, the cardboard cake board can have lines in them and the icing may pick up those lines when doing the upside down icing technique. When I turn it right side up I use a covered cake cardboard. All in all it's looking not bad and you have the technique down.
There is a tutorial on icing squares cakes as well. Let me see if I can find it. It isn't done with the upside down icing technique but you might be able to adapt it.
Here it is, scroll down to the post and pictures by B Keith (Ryder)
http://forums.egullet.org/index.php?showtopic=70728&hl=sharp+corner
I love using IMBC I find it way easier to smooth than buttercream. I just plop it on the top of the cake and start spreading it to the sides. After I get it somewhat smooth I take one of those yellow/orange things that drywallers use and smooth, it will take all of the airbubbles out, seems to work really great for me, not too sure what it's called though maybe a putty scraper or something like that. They come in so many different sizes. I did my snowflake cake with IMBC and my first princess cakes with tiara's (the picture with two princess cakes).
I also only use my whisk beater when I'm making IMBC, haven't had a problem except for some air bubbles but like I mentioned they do come out...
Antonia those cakes look great.
Zamode you look like you have the method down just need to perfect it. It still looks smoother than any of my cakes by far
Can I just ask what IMBC stands for? I'm figuring out that it's "something" butter cream but I don't know what the "IM" is. Thanks!
My one main question got answered, about what it is, but now how do you make it and how is different for regular butter cream? by the way the cakes are great looking.
...so can you use meringue powder instead of real egg whites in the IMBC recipe?
I made this once and it had a tart after taste...I am thinking it was the meringue powder. I keep hearing so many good things about the recipe and I want it to work....
And geez, antonia, your cakes look amazing! Those are both covered in IMBC???
My one main question got answered, about what it is, but now how do you make it and how is different for regular butter cream? by the way the cakes are great looking.
Both Italian meringue buttercream and Swiss meringue buttercream are a cooked or heated icing with no powdered sugar or shortening. The recipes are similar but the method for making them is a bit different. Here is the one I use. I prefer it because it is light and fluffy, less sweet and goes on so smoothly.
http://cakecentral.com/cake_recipe-2426-Italian-Meringue-Buttercream--Shirleys-Method.html
I would not use meringue powder in this recipe only because I can't stand the smell or taste of meringue powder. That is the tartness you were tasting in the icing, nasty stuff.
I would not use in this recipe only because I can't stand the smell or taste of . That is the tartness you were tasting in the icing, nasty stuff.
Amen to that Shirley! Thank you all for your help and advice! I've yet to try another cake with it, no cakes on the horizon right now but will post back with any questions or results. Great stuff, I love it and I really think the upside down method is going to help me with a little practice. 
MemphisMom9801, here's a list of acryonyms:
http://forum.cakecentral.com/cake-decorating-ftopict-2926-acronyms.html
HTH
It takes colour really well & does super sharp edges (with practice!
). It's the main icing I use in most of the cakes in my photos:
Okay Antonia, now your just showing off. Those are so perfectly iced and smooth as satin. What type of color does you use with meringue icings? I have used airbrush liquid at times because the paste seems to not blend in completely and leaves little dark spots of color in the icing.
I would not use in this recipe only because I can't stand the smell or taste of . That is the tartness you were tasting in the icing, nasty stuff.
Amen to that Shirley! Thank you all for your help and advice! I've yet to try another cake with it, no cakes on the horizon right now but will post back with any questions or results. Great stuff, I love it and I really think the upside down method is going to help me with a little practice.
Yep, just keep trying different methods until you find the one that works best for you.
Quote by @%username% on %date%
%body%