I've noticed that many Latin verbs can be turned into nouns (like the English do and doer). But, what's the process of this in Latin? I can find some terms in dictionaries, but most don't seem to have entries for such a thing.
Nihil est magnum somnianti
Nothing is great to a dreamer (= to one dreaming)
Be careful, though, because in the ablative singular the ending is an e instead of an i when it's used this way. This works for both the masculine and feminine.
The other way is to take the fourth principal part (i.e. either the perfect passive participal or the supine*, drop the ending, and add or to it. For example, take the word servo, servare, "to save." The fourth principal part is servatus, which would give is servator, "savior." The feminine form would be servatrix. For neuter nouns, the ending is -trum, which is how we get words like rostrum (from rodere).