Remember that the person with the board state always wins the game, thats why you need to make sure that your opponent isnt able to build up their board by getting rid of threats
Illustrative report
Mega Lucario ex Decklist: Riolu (x2), Lucario (x1), Mega Lucario ex (x2), Bonsly (x2), Hitmonlee (x2), Professor's Research (x2), Cyrus (x2), Copycat (x1), Korrina (x1), Arena of Antiquity (x2), Rocky Helmet (x1), Pok Ball (x2) The aim of this deck is simple: get Mega Lucario ex to hit for as much damage as possible
For many buyers, older EX and GX are more about collecting than current competitive play
The process varies slightly, but you'll typically need to select a service level (economy, standard, or express), package your cards carefully, and ship them to the service with tracking information