Straight gasket lips, new gaskets, clean gasket surfaces, load spreaders and proper torque are the keys. Most people tend to over torque valve cover gaskets and exaust manifolds.
Oil leaks or oil weeping? Many people can be way to picky about what is normal too. If the oil is running down the sides of the engine, I would say that is an oil leak and a problem. If there is just residue oils (or weeping) that is considered normal on early engines.
