Do notify the bureau of your new call sign as you upgrade. Please send SASEs with your new call, in addition to SASEs with your old call. Do include a SASE with any information request to the bureau. Do notify the bureau in writing if you don't want your cards. Don't send domestic US to US cards to the various call-area bureaus.
Overseas delivery is very slow.
Many cards coming from overseas bureaus are over a year old. Don't send your outgoing DX cards to your call-area bureau. Don't send SASEs or money credits to the ARRL Outgoing QSL Service. Don't send SASEs larger than 6 x 9 inches. SASEs larger than 6 x 9 inches require additional postage surcharges.