Hi,How do you know what SID and what STARS to use in a specific flightplan? (i.e. from KMCO to KATL).Thank you~!

One way that is fun (for US routes), go to flightaware.com, select Statistics from the top left menu, then click on 'recently used IFR routes'E.g., enter KMCO & KATL; it gives you the last couple of days of actual routes flown. In this case, JAG3 DBN CANUK3. You can play with it more, selecting the airline flights that flew this route and see the actual ground tracks. Note that filed altitude often correlates to type equipment.The direct approach is to review all the charts and pick the one that best suits your desired route. But even this has gotten easier with many sources on-line with charts in pdf format.Hope this helps