Where to get power for accessories?

I'd usually start by deciding when I want it to have 12 volts (all the time? When the car is in ACC? IG ON?), and where I want it (in the cabin? out under the hood?) and then start looking in the wiring diagram:

Toyota Service Information and Where To Find It | PriusChat

Sometimes you even find your trim has a fuse slot already present that isn't used, and the inner-circuit diagram shows you which connector terminal it comes out on.

Of course, how much current you want also matters. It wouldn't be a good idea to use a larger ampacity fuse in a slot that was intended for a smaller.

 

What type of lighting? Depending on how much amperage you're going to need, there are likely
fuses that aren't being used you can tap into. Like the heated seats? If you don't have heated
seats, you can use that spot.

 

More lighting for what? How many watts are the lights? The wiring you would do for exterior lighting is way different than what you'd do for interior lighting