I used to over-do it, but have a simple rule: get at least 50g a
   day. I'm a big guy - 6' (2m I guess) tall, medium to large frame
   and a minimum of 50g and a max of 100g, is easy.

   Takes no thinking really. As long as you teach yourself how to
   look at food and guesstimate the amount of protein within it,
   you can do a quick mental calculation.