I live in Ireland and what I do it go on the United States Postal Service ebay website and buy the stamps called "Forever Stamps". Just remember that you will need 3 forever stamps on your return envelope (large envelope)

Two options.

Step 1.

Visit www.usps.com which has a calculator to price your return envelope.

Step 2.

Get hold of some paper US currency from a bank, travel agent etc and include enough to cover return postage.

Or

Buy these stamps from the USPS eBay shop :
https://www.ebay.com/itm/USPS-New-Moon-Global-Forever-International-rate-stamp-pane-10-/222114125583?hash=item33b708970f

And use them on your return envelope. $11.50 divided by 10= $1.15 per stamp.

Then take your request to a Post Office to have them weigh it and pay for postage here.

This is my first time sending fanmail and I'm looking for help and instructions. I live in the UK and would like to send a letter and a photo to Betty White for her to sign and then send back to me in the UK. What is the simplest way to do this? Thanks in advance for any help.