There are a lot of great strategies and tales of accomplishment on these forums that are great for learning. What about blunders? Things that you will always remember to not do! I am sure this is a really noob mistake but I built a rush strategy on sieging my enemy with warriors thinking that once I hooked up my copper I would be able to upgrade my warriors outside his city for immediate attack. I am sure it is in the manual, but ... I doubt I will ever forget now that units can only be upgraded in your own territory. So, let the blundering begin!