How do you make windows?

Hi all,
How do most people go about making windows, do you reuse old along with all the trim and items to make it stay in/weathertight, do you purchase new, or do you fabricate? If so how do you fabricate?
I am thinking about making a trolly top and I am trying to figure out the top windows. I am also thinking the door windows through, I want a good amount of screen for max airflow. The trolly top will likely be fixed windows.
Has anyone made a double door like on a commercial RV, inside door is screen and outside door is hard with fixed glass? I am thinking I want doors on both sides.
Thanks
Stan
How do most people go about making windows, do you reuse old along with all the trim and items to make it stay in/weathertight, do you purchase new, or do you fabricate? If so how do you fabricate?
I am thinking about making a trolly top and I am trying to figure out the top windows. I am also thinking the door windows through, I want a good amount of screen for max airflow. The trolly top will likely be fixed windows.
Has anyone made a double door like on a commercial RV, inside door is screen and outside door is hard with fixed glass? I am thinking I want doors on both sides.
Thanks
Stan