What distinguishes science from pseudoscience in your view?

Science is the means of predicting the future. Anything that follows strict laws of nature can be predicted within an orderly system. With increasing chaos (which is the increasing number of relevant variables and iterative feedback loops), the timespan for prediction shortens exponentially, thus the validity of scientific models becomes less relevant. In an overly complex system you might create a scientific observation, which is so tightly specific in the constellation of the underlying variables that it is utterly useless in predicting anything else. Science favours simple models (Ockhams razor) and struggles to deal with complex systems.

Science tends to take itself way too serious as it claims to be based on factual evidence. But to every controlled variable of an experiment, there are often plenty more variables that are not controlled for, not even realized to be important. Especially within the life sciences, merely following a protocol does not necessarily lead to the same result as you are dealing with living matter that is so incredibly complex that one could say it has a will of its own to some extend. Many things come down to experience and understanding the material you are working with and also being skilled in the handling of said material. These aren't the hallmarks of science but of a craft, yet it is still possible to derive scientific conclusions.

Any observation within an controlled environment can be scientifically valid. It has to be determined whether the controlled variables are the actual variables that led to the observed outcome. Science isn't based on there being an existing body of knowledge, but a means to create said body of knowledge. Contradicting the established understanding doesn't automatically invalidate the made observations, as no scientific theory is final or perfect. Science apart from its romanticization tends to be a war on beliefs, a battle of the ideas. Wrong theories can take a long time to be accepted as inaccurate and to be overhauled by more useful theories.

Science is inherently conservative and not at all open to change, only open to addition. As soon as a theory gets established and acknowledged as applicable, it requires enormous amounts of evidence and thus invested time and money in order to overturn it. This is a fault at times, but most of the time it's rather benefitial, as a well reasoned theory gets things right most of the time and just needs some tuning in the details. On the other hand, if a theory is plainly wrong and taken for real because scientists at the end of the day are humans and have a moral ideal of how the world *should* be, this asks for disaster, a pseudoscience declared science.

No matter how peer-reviewed, theoretically/experimentally sound, and logically consistent one's science may be, always remember one thing. Pseudoscience is a belief mechanism rather than a scientific one, and as such, can bend the felt reality of those subject to the beliefs. Case in point: a large study on astrology proves that date and time of birth have zero correlation on personality or professional outcomes. However, on dating sites, given that people believe astrology has this power, people choose mates based upon the misconceived pseudoscience of astrology, thus turning the belief into a reality. The bottom line is to respect the power of the belief in pseudoscience, even if there is no data supporting any correlated effect.