It is a difficult question to answer. I can point to various studies but I must keep in mind that those that made me aware of such studies are not necessarily unbiased.

Any useful tips and heuristics?

That depends. You need to know just what you want your kids to be like. And that has to be what you really want your kids to be like, not what it sounds good to say you want your kids to be like. For example, spanking kids will make them more likely to be physically aggressive. But this may well benefit them in the long run, teaching them tactics for maintaining higher status and so improving their health and happiness.

There is a clear negative correlation between childhood spanking and IQ. But given that your child's genetic heritage is already determined, your own choice of behaviour quite possibly has no causal influence on the IQ outcome. Low IQ parents are more likely to be physically (rather than verbally or socially) aggressive and also more likely to pass on genes for low IQ so causal influence from the spanking is doubtful.