What were Ford's main achievements in foreign policy?
Gerald Ford was president for only a short time, a time during which there were not many opportunities for him to distinguish himself in foreign policy.
Ford's main accomplishment was probably the signing of the Helsinki Agreement in 1975. This agreement continued the policy of detente that had been started by President Nixon. In it, the US agreed to recognize the legitimacy of the Soviet Union and its control over Eastern Europe. This may be seen as an accomplishment because it furthered the cause of peace between the two countries.
Ford also managed to push Israel and Egypt to work to improve their relationship. He was much more blunt with Israel than US presidents typically are and forced them to come to terms with Egypt on the issue of the Sinai Peninsula. This helped to repair relations between the two countries.
Outside of that, Ford did not really have time to do many things that would be seen as accomplishments.