They analyse order flow and price patterns (like in forex), also you should pay greater attention to contract specification, i.e. when futures expire, its size, type of delivery (cash-settled or physical delivery) etc. Also futures with different maturity dates can be traded simultaneously in the market which creates such useful tool for analysis as futures curve (function of futures price depending on maturity). By analysing relative change in prices you can see how demand on the asset changes from now to future.