I am making a cake topper for an upcoming bridal show and have 12 large yellow roses - I bought a
small green styrofoam half circle (4 inches) and was attempting to arrange them. This circle now seems to be too large. Could someone offer some advise on how you assemble the flowers once they are done so it looks like a nice bunch of flowers on top without any gaps?? Thanks so much!

Fill in the gaps with leaves or small filler flowers.

Wish you could watch Jennifer Dontz's dvd on flower arranging. You're right. The dome is too big leaving you with alot of space to fill. She uses about a 2 inch square of styro. You will have to make some smaller flowers to fill or if you have time constraints, some looped ribbon or fanned tulle on picks.

Looped ribbon is very pretty.

http://cakecentral.com/gallery/1313089/yellow-brown
I put the link to the cake I am trying to make a topper like - it is by daily and called Yellow and Brown....
I LOVE this cake and I think it's one of the classiest cakes I have ever seen, so I am making one like
this for the bridal show - I think the brides will love this!!
Maybe I'll send her a msg. directly - but if someone who sees this topper has more info. please let
me know. I really don't want bow loops or leaves in there - I love the look she achieved.
Thanks so much!!

Smaller styro.

Can you make some extra petals in the same colour as your roses and insert them where there are gaps? I also second smaller styrofoam. When I did one of these with smaller roses, I needed lots more roses than I originally thought. I'd definitely use a smaller base next time.

Also, cover the styrofoam with yellow fondant, it will help hide any gaps.

I typically cover a small styro half ball in fondant and then make varying size flowers so that I can fill in any spaces. I usually transport the nosegay seperately and attach at the venue

I don't use styro at all. I pipe a big drop of buttercream. I then arrange the flowers balancing on top and adding buttercream wherever needed. I use the same technique I use for bows.