I set up a place to grass cast at the main part of the farm. There's a old garden patch that we stopped using and it is big enouh to layout flags sort of like the FFF Master test describes for accuracy and distance. I even optimistcally put a flag at 100'

I have 35, 45, 55, and 85' flags. Strech a tape out over the 100'.
Testing it I can tell by the tape I'm not as good at distance as I thought (70').
Is this over board? Where do you all practice when not on the stream?