Janet, it depends on the size of the object. Small things willsolder easily enough with one of the liquid fluxes such as Battern'sbut larger ones need the white paste sort.
What is the best flux for hard-soldering sterling?
Others may differ, but for me a paste of 20 Mule Team Borax (fromthe soap section of the grocery store) & water works well.
Marilyn, What are some brand names of white paste fluxes?