actually, it's my 2nd time using pin hole. In fact, using this small little box is so fun. I basically throw all the text books and meters away... all I needed was a mobile phone with a stop watch. Spend time taking composition and find a suitable instance and just open the shutter.
It's back to basic 101 where composition is the key to good photography.
Using the small hole, expose for about 8sec on a sunny day and viola... even if over expose for 2 to 3 sec also doesn't matter... it's that simple.