When I set throws....I place a ruler at the back of the control surface....so that one end of the ruler is resting on something on the table, so that I have a good starting point that doesn't move...like I'll put the 5 inch mark centered on the elevator (5 inch mark is just an example). then set throws so that I get a 1/4 up and down.
There are other ways to set throws like a throw meter, but the above method works ok
Good flyin