Let's say you were thinking of making a docufiction about alien life and you wanted to do a segment or two about alien life with radically different biochemistry, such as being based on silicon instead of carbon. How are you supposed to show any of this? How can i even begin to think of what such bizarre life could look like?
Maybe start looking for special chemical process that will differ from what we have on earth, and try to use it in some situation. For example, find a material the reacts with silicon but not with carbon and use it to harm the alien or something like that.
Another option could be tell in a more subtle way, like having a silicon alien calling a human a overdeveloped coal as a swearing, or calling the silicon alien a overdeveloped breast implant