it doesnt take much. Look at the stuff, look at the numbers, see what the scouts say and go from there. Its pretty easy to ferrett out the BS when you do your own leg work.
Just like some NESPN idiots who like to change their opinions on a dime, you learn who you should and who you shouldnt trust. Sure, the NESPN morons are good to hammer home a point, but some have been VERY wrong on guys who arent even that much hidden.
Case in point. Keith Law is a moron. I have used him to add to my points and discredited him when he doesnt. I know, bad moves, but still. He has said many times that a guy like Alan Horne (Yankee AA pitcher) has a future as nothing more than a #5 or a mopup man because he tops out at 90mph and has no movement. Then, 2 weeks later, he says Horne has a future as a back end of the rotation pitcher and tops out at 92 with his 4 seamer and has a mid 80s 2 seamer. Fact is, you go through scout.com (Yankee section only) and every now and then, through BA, and you will get the actual scoop. BUT, the best is if you go see them for yourself. I've seen Horne in Trenton this yr. He tops out at 96 and sits at 92-94 with his 4 seamer and tops out at 92 with the 2 seamer (sat right behind a scout with a juggs gun too to confirm the scoreboard readings when I wasnt too busy filling my face with hot dogs and nachos).
So overall, it doesnt take a lot. Just simple paying attention and interest can get you all you need. And none of us are experts. I dont think anyone can actually call themselves that because an expert wouldnt be wrong 3/4 of the time, like so many of these so called experts are.