From Paul Brians’ book Common Errors in English Usage (to which he allows access at no cost at the Washington State University Website), here is a worksheet on the use of the adjective, adverb, and preposition regardless. The gist of this work involves understanding that irregardless is a redundancy–and therefore a solecism in prose. In any case, this is a full-page worksheet with a three-sentence reading and ten sentences to rewrite.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.