To make my Arcee, I merged an action figure and a model kit, making this more of a "true" kitbash. The action figure was the doesn't-look-at-all-like-Uma Poison Ivy figure, and the model kit was a "Net Defenders" knockoff of the Panzer Blade "Galient" model kit. The Galient is a semi-transforming robot, which is to say it becomes something vaguely like a jet in the same way many Gundams do.
The preparation for Poison Ivy mainly involved removals. I pulled off the head, cut off most of the hair and cut the nose to the triangular prism shape Arcee has. Then I covered it in Sculpey, which I'm finally getting the hang of smoothing properly, and fashioned a likeness of Arcee's helmet hair, with a few modifications. On the body, I found I had to carve off much of the calves and feet so that they'd fit inside the hollowed-out Galient boots. Additionally, I fused the hip joints, since they weren't circular and would expose dark green plastic when moved.
I had to hollow out the Galient boots and forearms to fit around the limbs of the figure, and did some other carving on the torso pieces. I tried hollowing out the pelvis pieces, but they were too full of bits and ended up shattering. Oops. Improvising, I took a hip flap and cut it to fit over Arcee's abdomen, adding the circular stand for the pilot as a decoration. The wingflap which would have attached to the rear pelvis piece I simply glued to Ivy's butt. I tried including the jet nosecone in the backpack unit, but I realized it wouldn't fit with the larger head I was making, so I removed it and turned it into a gun. A couple of interior joint pieces became Arcee's G2-style (remember all the weapons Sideswipe carried in the comics?) wrist blasters. And I kept the sword, since the figure could hold it. Finally, deciding the shoulders looked a bit bare, I managed to modify the shoulder pieces of the Galient into shoulderpads for Arcee.
In painting the figure, I found that my pink was a little too vivid, so I mixed it with the last of my gloss white to tone it down. Since I no longer had any gloss white, I decided to use very light grey for the body instead, again keeping with the G2 tone. Plus, the light grey covers dark green much better than white does. :) Using a technical pen and a silver gel pen I added black and silver line accents to the figure, including a lot of detail on the Autobot symbol which doesn't show up at ALL on this scan. Sigh.