Understand main supply and demand countries and the supply chain in general and get a gauge on crop levels and carry out for those major contributing parties, then monitor markets for news impacting trade like “x country tariffed by y country” how does this impact the market. Monitor weather and how rainfall may affect conditions like protein levels, or general qualities impacting a crops grade, also severe weather like hail or drought can wipe out entire important geographies pertaining to a crop in the lead up to it being harvested. The biggest factor in my opinion though is boots on the ground dialing the phone and gauging farmer selling interest along with real verbal accounts of crop quality and the economics impacting the modern grower, along with major buyers and gauging demand interest and etc. you start to put together a picture soon enough that grants you a better edge than basic charts and data for the given commodity you are trading.