I don’t think, there are some documents like that (at least not official ones), but if you go by python, I’d recommend you to follow the PEP 8 style  47 as this mostly applies to pytorch as well. There are a few pytorch specific things, I’d append:

don’t use autograd of not necessary (use with torch.no_grad() if possible)
only push tensors to GPU, if they are actually needed
try to avoid loops over tensor dimensions (slows things down)
try to free graphs as soon as possible (use detach or item whenever you can) to avoid memory leaks

If there’s anything coming up to my mind, I’ll just edit this post.