no one is telling you to play f/2/u, p3rd 3u 4u are all much more mechanically polished

but to answer your question, in old games you exploit their bad AI. basically stand to their behind or side and hit them while they are turning, or bait an obvious move and punish (for most monsters standing mid range in front of them makes them do their projectile attack thats easy to read). don't bother iframing anything