Hi I am trying to make a present cake with the top lid open with flowers around it and a suitcase cake with the lid open revealing it contents. Thanks in advance.
For the open box, you can make the top separately out of gumpaste. First cut a circle a tiny bit larger than the cake pan you used for the cake. Once it's dry, turn it upside down and glue a strip of gumpaste around it with melted chocolate for the rim. Place the flowers where you want them on the decorated cake and then place the lid at an angle over the top. You can support the lid on the side where the flowers won't be sticking out with a piece of fondant or some RKTs, if you need to. If the suitcase lid is only open a fraction, then you could do it this way, too, just being sure that the back edge of the cake and the lid meet and you put in some really cool fondant hinges. If the suitcase is to be open at a 90° angle or more, I'm not sure quite how, but I would attach the two parts by putting some fairly long skewers into the back edge of the lid (the details of how to do this depend on whether the lid is gumpaste, RKTs or something else). When it comes time to assemble the cake, the skewers go into the cake that's the bottom half of the suitcase.
I just found this little gem, posted by chocolate1 on another thread, but it seems to be the answer to the open suitcase dilemma, as well:
"For anyone who has tried to attach the foamboard "monitor" for a laptop cake..it can prove challenging...after many attempts from different suggestions, as I was driving, and asking for "divine guidance" on how to rectify this issue, "L" shaped brackets came to my mind!...so I bought 2 L shaped brackets, placed them in-between the 2 foam board pieces that were the monitor, then slid the other end of the L bracket under the fondant covered cake..and it worked...it worked great!...nothing else to do to stablilize the monitor..the brackets could not be seen, the monitor was "free standing"!...L brackets are the answer...its the only way I will ever make a laptop cake in the future! I had to pass it on to all of you...Happy Icing!"