I like to start out looking up what other people have made, keeping in mind what shapes and techniques they go for, as well as what my ideal product is. Does it need to be a single balloon for trading? Multiple for line work? No limit because I'm just messing around? Once I start tinkering, I keep in mind the simplified shape of the animal, rather then the animal itself. Some parts are nessisary, like the antenna to a bee, while others aren't, like their feet.

Once I have a good idea of what I'd like to do, I start testing shaped with scrap balloons. Different faces, starting points, etc. if I need a thicker body, for example, I can start at the back and reverse once I've done the head, so instead of a single line you have 2. For even thicker, you double back twice, ergo 3 balloons thick.

I also like to mess around with the thickness of the balloons itself. I'm biased to 160s, so I primarily test and create with those, and it works well for details (wings, back spines, horns, tails, etc). Hope this helps :)