Getting the cricut design space images to cut cleanly and precisely was very much a struggle. Illustrator will produce SVG files and that should allow for very precise cuts but trial and error has taught me that design space will adjust the image despite having a clear path.
The basic problem: Imported images do not cut as nicely as they should.
Vector your art
Taking the original art and making it into a drawing with a very smooth outline is going to the be the first step. By creating a vector of the art it becomes a line drawing that can be infinitely scaled while still maintaining the integrity of the shape. If you are planning to cut this as a single vinyl either for a sticker or a stencil it will be important to make sure you only have black, if you are going to layer you can use as many colors as you intend to cut. If you are going to cut single color make sure that it looks right in only black or in the case of a vinyl for a window, only white on a black background.
Throw it into photoshop
Create a canvas that is at least 2400 x 2400 pixels keep the background blank (not white). The size of the canvas allows for you to paste in the vector as pixels in a high resolution in a large size. Doing it this way allows for fine detail control when editing as well as a good translation by design space. The vectored image may not be exactly what you are looking for, keep in mind that if you aren’t planning to layer the vinyl you need to make sure you know what will be visible and what will not. Sometime you may want to completely add or remove lines. If you decide to make a lot of changes it will be good to go back to illustrator and produce a new vector version of your image.