whirlpool/ hop stand duration and temps

I've been using hop stands for all of my beers, but they all have been slightly different. I was wondering what you guys would recommend in terms of when to add the hops (at what temperature) and for how long. I add a minimal bittering charge at 30 or 15 min depending, then add the rest of the hops during the hop stand. Usually the hops stand is about 20 min, then I turn on the wort chiller and run it until its cold enough to pitch (66-68F typically). If you guys have any recommendations, I'd appreciate it. Thanks! Also, I do dry hop after fermentation is complete and let that stand for 4-5 days.