The F shift or "Fantasy Shift" is the beginning of the shifting journey. In this shift, you will decide everything about your new mer body.
The first thing you need to do, is pick out what type of mer you want to be see the "mer types" page for information. You will then decide what your tail will look like.You can draw your tail if you wish, or you can go on google and look up silicon mer tails. Good mer tail designers to look up are merbella studios and mertailor. The next thing you need to choose is any extra amenities you will have.
Lungs: If you decide to shift lungs, I recommend modeling them after a dolphins lungs. Lungs are best if you plan to occasionally go on land.
Gills: Gills are harder to shift, but they are best if you don't plan on coming on land.
Webbed fingers: Webbed fingers are really useful for quick swimming.
Claws: Claws are a good way to protect yourself from various ocean predators, they are also useful for catching fish.