hello im In Canada , im new to this TTM thing im wanting to send a few autograph requests to a few celebrities in the USA , what postage should I use sending to the celebrity and what postage should I be using to have them return me SASE , ive heard that the Global Forever stamps work

hello im In Canada , im new to this TTM thing im wanting to send a few autograph requests to a few celebrities in the USA , what postage should I use sending to the celebrity and what postage should I be using to have them return me SASE