Yea, I "stand like a tree" during lunch on the yard at the back or the factory where I work. Check out "stand still be fit" youtube vidios they were on England's PBtv. It would be an easy search. I also do walking meditation or some other qigong. If you don't find Zhan zhuang day 1 with a quick search leave me a message.
To cultivate Qi you got to do the work don't worry about details that is what study is for, ask teachers questions you have! don't lisen to answers you have not requested (with a question.)
go play and enjoy the now at lunch.
sward