Best way to set Cooking Temp on 640

Hi All,
Can anyone out there give me the best way to set the cooking temp...? Do you set it for what you want to cook ( 220 ) and wait for it to get to temp and it holds... Or should you start higher such as the default temp (350) and then lower it when your ready to put the meat on?
Can anyone out there give me the best way to set the cooking temp...? Do you set it for what you want to cook ( 220 ) and wait for it to get to temp and it holds... Or should you start higher such as the default temp (350) and then lower it when your ready to put the meat on?