There are many Goddesses in the different pantheons. Most people will simply pick a particular Goddess and simply use the name for all rituals and spells. Others prefer to vary the use of a name depending on what they are requesting. Example: If you are asking for protection, I'm not sure that calling on Aphrodite would be appropriate. This is where the variation would come in.

For now that is the best information I can give you. Hopefully, I'll find the time soon to type up all the information I have on the dieties (male and female) from almost every culture.