In general: never call! Of course you don't want to be too predictable, so once and a while you mix in a call. The general idea is to raise a lot and back out early with real garbage if you are reraised (always check out those raises in the beginning: is the guy a bluffer?). My experience is that it is just too difficult for most players to reraise you with something like 62 offsuit. So in general, their actions are pretty well readable:
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