Over time I have refined the design (to some degree) as I needed. This is the case I use every day. Eventually I will probably find some flaw and redesign the thing, but until this this is what I am using

The Lid in the packed files has the lettering on it, if you don't want that, there is a version without it included.

Print the Tpu part in Tpu 

Apologies for the poor picture quality, I had to use a external camera.