strict routine, maybe have an A and B day for chest day, where a couple exercises are different to some degree. I do this for legs as well where one is more of a squat and quad dominant vs other more deadlift and the back side. But a specific routine usually is best if done properly. The key here is having some sort of progression built in, whether it be reps and/or weight increases etc. If you can manage that doing something different every time more power to you. But I like doing cyclical periodization in my routines, among other strategies. But I'll also change a focus a bit for months at a time etc. When I was following somewhat of a westside template I would change my max effort exercise every week, but I would come back to it several weeks later and always try to push it higher, in fact if I did the same ME movement two weeks in a row I would be weaker the second time. Point in bringing this up is there was still progression even with the routine changing, but even then it was still a strict routine.