I was asked to discuss this topic, but I'm doing so based on my own in-person baseball autograph experiences. So if you have any comments or anything to add please feel free to!
Tips on getting autographs:
• Get to the ballpark early! I've found that for night games many players start arriving as early as 12:00 noon, and for afternoon games they can arrive as early as 8:00am, so plan accordingly. Coaches are usually among the first to arrive. If you can get anywhere near the player parking lots/dropoff areas this is the place to go. I know a lot of people hound the visiting teams' hotels but that seems a bit much to me.
• When inside the ballpark I guess each place has its own rules, but generally try to get down close to the dugout of the team you're trying for. Sometimes players sign along the rail, other times they'll have a stadium employee hand them items over the dugout to sign. Just pay attention and be aware of what's going on.
• Hang around after games too in the same places you hung out before the game. Most players will start exiting about 1/2 hour after the game.
• Say "Please" an "Thank you." Remember, the player doesn't HAVE to sign anything, so be grateful they took their time. Plus many times a simple "Please" will be enough to get a player to sign for you. Say "Joe Player, will you please sign?" as opposed to "JOE!! JOE!!!!! JOOOOOEEEEE!!!!!!!"
• Always bring something to sign WITH. Nothing is more annoying than the guy that keeps asking you to use your pen - don't be that guy!
• Don't yell out bad things if the player doesn't sign at first - that's a sure way to get him to not sign at all!
• If there are a LOT of people trying to get autographs, don't ask the player to sign multiples or add inscriptions. That only takes more time away that he might use to sign for someone else.
• If there are any around, stand near little kids. Players always go to them first so if you're nearby you might get lucky.
• The above rule also applies to good looking girls. (hey, it may seem like a sexist statement but it's true! )
• Don't push other people (especially kids) out of the way. That's just rude. If you can't get in the front you should have gotten there earlier. Players will recognize ignorance. If I see a little kid behind me I'll try to squeeze them up front. Getting the autograph may be great for you but for a kid ballplayers are almost superhuman, they'll remember things like that for life.
• Don't send little kids to get autographs for you. That's just horrible.
• Have something decent for the players to sign. A lot of players won't sign blank cards (like index cards).
• Don't get the player to sign that day's giveaway if it has nothing to do with that player or that player's team. That's stupid. I've seen visiting team players in Philly sign Phillies hats and such. Why would you do that?
• Don't ask the player "Who are you?" If you don't know you probably don't need their autograph anyway.
I hope this helps and I expect to see more in-person autograph threads now.