Here are a handful of examples of E-6 (positive film or chromes) cross-processed in C-41. These images were shot on Kodak E100VS rated at 50ISO. As you can see, most of them are shot with axis lighting, meaning the sun is directly to the photographers back shining straight on the subject. If you shoot in other lighting situations expect there to be some color shifts especially in the shadows. Cross processed images will only achieve this look when shot in very sunny situations that are directly lit. If you shoot in the shadows it would go very green.
As a rule of thumb, the exposure for directly lit subjects at 50ISO is F5.6 @ 1/500th. Again, this is a starting point so if you wanted to shoot other F-stops or shutter speeds that is where you can start as a guide. Also as a side note, Kodak E-6 will produce this warmer look (red/yellow) where Fuji E-6 is very blue and green. Most E-6 films have been discontinued but are readily available on Ebay as either fresh, recently expired or super expired (5 years or more). Depending on the age and stock of the film, the color rendition can be very different. But it is cross-processed so there might be some leeway in achieving your “perfect” color.