to dot the i's and cross the t'sponer los puntos sobre las íes
(emphatic, to avoid ambiguity)yo
Note that subject pronouns are used less in Spanish than in English - mainly for emphasis, to avoid ambiguity and in comparisons.
I'm not one to exaggerateyo no soy de los que exageran;it is I who ...soy yo quien ...;he was frightened but I wasn'tél estaba asustado pero yo no;if I were youyo que tú;Ann and IAnn y yo;he is taller than I ames más alto que yo
Don't translate the subject pronoun when not emphasizing or clarifying:
I've got an ideatengo una idea;I'll go and seevoy a ver