One of my favourite purchases in the last few months is definitely my Cassie Brown Airbrush.
This has become an essential tool for all cakes with a base colour that isn't white...tho I definitely recommend making a spray booth if you use one
Once covered the first step was to mix up a nice pale pink for the cake itself as all the detail was going to be in white and dark pink.
Another essential purchase for the next stage of creating the cage is a clay extruder, the one I prefer for ease of use is the Makin Professional Clay Extruder.
once i had created the lengths I needed (could get 3 before having to refill the device), i would use a water brush to wet the line they would follow, and starting at the bottom frill in one of the gaps, gently press the fondant to stick it to the cake, once at the top just trim off the excess, it doesn't need to be perfect as the top will be covered up.
The top decoration was made by cutting out three circles in flower paste, so they set hard, these were stuck together with the smallest being rolled into a ball.
You could also create a loop as a "handle", there are a lot of great ideas on Google and Pinterest.
All the decorations were stuck with Royal icing that was made earlier to decorate the birds.
The birds were positioned and stuck to the bars of the cage...you may need to place them at a height where you can position a glass or something underneath to support them temporarily while the royal icing sets.
The rest of the flowers and leaves were then placed onto the cake, beneath the birds in particular to give them a perch, and then in key places to enhance the overall effect.