All three of these involve unchecked or blind use of heuristics. As such, one strategy is to slow down and formalise the logic chain, using more reflective and less automatic reasoning. Another strategy is to monitor or uncover one's motivation. From Wikipedia:
A heuristic [...] is any approach to problem solving or self-discovery that employs a practical method that is not guaranteed to be optimal, perfect, or rational, but is nevertheless sufficient for reaching an immediate, short-term goal or approximation. [...] Heuristics are the strategies derived from previous experiences with similar problems. [...] These rules work well under most circumstances, but in certain cases can lead to systematic errors or cognitive biases.
In the case of misconceptions, attribute substitution replaces parts of the problem at hand with seemingly comparable substitutes that are better known from one's personal experience or education. If one is lucky, the relationship between the actual parts (of the current problem) and the substituted parts (of the known heuristic) will match sufficiently, giving a usable solution. But if by chance these apparent similarities are partly or wholly illusory, the solution is likely to be wrong and unusable. From Wikipedia:
Attribute substitution [...] is a psychological process thought to underlie a number of cognitive biases and perceptual illusions. It occurs when an individual has to make a judgment (of a target attribute) that is computationally complex, and instead substitutes a more easily calculated heuristic attribute. This substitution is thought of as taking place in the automatic intuitive judgment system, rather than the more self-aware reflective system. Hence, when someone tries to answer a difficult question, they may actually answer a related but different question, without realizing that a substitution has taken place.
In the case of assumptions and expectations, the perceived familiarity of the current situation to prior experiences leads one to assume that results of prior actions will be found again if one acts similarly to before. Basically, if the situation looks similar to last time (assumed parameters), and one acts similarly to last time (known schema), the results should be similar to last time (expected effects). Here too, one may get lucky and find the assumed result. But an apparent familiarity can be misleading if significant variables are unknown or ignored. From Wikipedia:
The familiarity heuristic was developed based on the discovery of the availability heuristic by psychologists Amos Tversky and Daniel Kahneman; it happens when the familiar is favored over novel places, people, or things. The familiarity heuristic can be applied to various situations that individuals experience in day-to-day life. When these situations appear similar to previous situations, especially if the individuals are experiencing a high cognitive load, they may regress to the state of mind in which they have felt or behaved before. [...] The familiarity heuristic is based on using schemas or past actions as a scaffold for behavior in a new (yet familiar) situation. [...] Individuals automatically assume that their previous behavior will yield the same results when a similar situation arises.
The underlying theme for heuristic errors in general is that our need for efficient operation leads us to make hasty mistakes of reason. Moreover, these mistakes are generally considered automatic and unconscious, coming from a brain system sometimes termed System 1 (see dual process theory). A slower, more systematic and reflective brain system, called here System 2, is said to override or manage the automatically activated percepts and schemas. From Wikipedia (cognitive bias mitigation):
[Our] reasoning mechanism [can be] segregated (approximately) into 'System 1' and 'System 2'. In this view, System 1 is the 'first line' of cognitive processing of all perceptions, including internally generated 'pseudo-perceptions' [...] By contrast, System 2 is responsible for 'executive control', taking System 1's judgments as advisories, [...] and then choosing which advisories, if any, to act on. In this view, System 2 is slow, simple-minded and lazy, usually defaulting to System 1 advisories and overriding them only when intensively trained to do so or when cognitive dissonance would result. [...] [Our] 'heuristic toolkit' resides largely in System 1 [...]
The higher our cognitive load, the higher the chance a heuristic will be applied without reflection. From Wikipedia (dual process theory):
Tsujii and Watanabe did a follow-up study to Goel and Dolan's fMRI experiment. They examined the neural correlates on the inferior frontal cortex (IFC) activity in belief-bias reasoning [...] This study provided some evidence to enhance the fMRI results that the right IFC, specifically, is critical in resolving conflicting reasoning, but that it is also attention-demanding; its effectiveness decreases with loss of attention. The loss of effectiveness in System 2 following loss of attention makes the automatic heuristic System 1 take over, which results in belief bias.
Some newer perspectives are more bitter-sweet about our ability to filter out heuristic processing errors when the right motivation exists. Our default approach is said to be that of a cognitive miser, who takes the lowest effort path to solving problems, or basically who accepts the advice of System 1 without question. But desire has a tendency to direct the flow of reasoning, which can either increase or decrease the proclivity for bias, depending on what outcome we want to achieve, possibly at the unconscious level. A capacity thus exists for being a motivated tactician. From Wikipedia:
In social psychology, a motivated tactician is someone who shifts between quick-and-dirty cognitively economical tactics and more thoughtful, thorough strategies when processing information, depending on the type and degree of motivation. Such behavior is a type of motivated reasoning. [...] Current research does not deny that people will be cognitively miserly in certain situations, but it takes into account that thorough analytic thought does occur in other situations.
Researchers have divided preferred outcomes into two broad categories: directional and non-directional outcomes. [...] Individuals motivated by directional outcomes have the intention of accomplishing a specific goal [-- particularly social and self-esteem goals]. If someone is motivated by non-directional outcomes, he or she may wish to make the most logical and clear decision. [...] Confirmation bias is an example of thought-processing motivated by directional outcomes. The goal is to affirm previously held beliefs, so one will use less thorough thinking in order to reach that goal. A person motivated to get the best education [...] is motivated by a non-directional outcome.
Hence, when the goal is to confirm existing beliefs -- either to oneself or to others -- the outcome is more likely to be biased in a self-serving way. On the other hand, if one has a vested interest in the quality of outcome, such as for self-mastery or discovery, then a more robust, non-directional outcome may be sought. From Wikipedia (goal orientation):
In general, an individual can be said to be mastery or performance oriented, based on whether one's goal is to develop one's ability or to demonstrate one's ability, respectively. [...] [Goal orientation] refers to how an individual interprets and reacts to tasks, resulting in different patterns of cognition, affect and behavior. [...] Individuals with a mastery orientation seek to develop their competence by acquiring new skills and mastering new situations. [...] Individuals with a performance orientation seek to demonstrate and validate the adequacy of their competence to receive favorable compliments while avoiding negative judgments. [...] A mastery orientation is characterized by the belief that success is the result of effort and use of the appropriate strategies. [...] A performance orientation is characterized by the belief that success is the result of superior ability and of surpassing one's peers.
Overall, the issue of avoiding biases and heuristic errors appears to be complicated, but as hinted above, certain mindsets and methods could in theory make a difference. Avoiding distractions, learning to improve one's focus, taking time to reflect, and striving for self-mastery and discovery, rather than validation, may help one to see more clearly.