Did you and I skip English class? Or was it you and me? I could go into the subjective (me) and objective (I) explanation. Things happen to "me" while "I" is the doer. But there is an easier way and here it is.
Drop the other person from the sentence and see if it still makes sense.
Example #1: "You and I skipped English class." or "You and me skipped English class." Drop "you and" what is left is either "I skipped English class." or "Me skipped English class." Clearly only one of these is correct, unless you work on Sesame Street. (Grammar point: "You and I" are committing the action and are the objects of the sentence.)
Example #2: "Class was canceled for you and me." or "Class was canceled English for you and I." Drop the "you and" here and the sentence reads either, "Class was canceled for me." or "Class was canceled for I." Again the choice becomes clear. (Grammar point: Someone else is acting, "you and I" are the subjects the action is happening to.)
Really, the bold type is the only part you need to remember to never make this mistake again.
By the way, my grammar loving husband wanted me to add that never, under any circumstances, would it be correct to write "myself" in place of "I" or "me."