How to know if I am getting the most out of my coffee roasting effert

[snakeoil]

Have roasted twice and the results seem to be the same as for as taste is concerned. In other words 2 totally different beans. Colombian Supremo and Costa Rica SHB Tarrazu Rubies. How can i tell if myself and my roaster(Behmor 1600) are doing our jobs?
Thanks for the help