there is alot you can do to improve you're calling personally yes, to an extent.
Really though, to be a great main caller is takes trust from your teammates and experience with your teammates etc. You can get away alot of the time with making a call that isn't always 100% the best thing to do, but if your teammates trust your call you can pretty much make any play work (unless of course its completely retarded) and just playing with your teammates will help you make calls better because knowledge of play styles on your team is a big part in the kind of plays you can execute.