For starters:Both are of similar introverted, stoic, emotionally restrained types.
Both Raven and Dooku practice emotional restraint in order to control their powers. Dooku is a noted practitioner of the Quey'tek meditation technique (Dark Rendezvous) which allowed him to mask his force signature and remain undetected by enemies. We also seem him regularly meditating in The Clone Wars which also adds to him being of the calm and collected personality. Only during rare, intense instances do we see Dooku sporting sith eyes in combat, coupled with anger and rage. This regular abstinence from emotions in itself is a deviation from the practice of most sith, but makes sense when coupled with the idea that the dark-side consumes those who can't handle it and their emotions. Dooku knows this, and is disciplined enough to circumvent it by always being the one in control. He knows that letting go of his emotions is a key to disaster and does everything he can to prevent it.
Similarly, Raven prefers to remain as emotionless as possible at the risk of letting her powers grow out of control. We regularly see her meditating alone and keeping a calm and collected demeanor overall. In the rare instances that we see her lose control of her emotions, she sports demonic eyes in the spirit of Trigon and loses control of her powers.
Both Dooku and Raven are calm and collected personalities and remain emotionally restrained, in addition to employing meditation techniques, to prevent their powers from taking control over their beings.
Both Dooku and Raven are introverted personality types who take pleasure in spending the majority of their time alone. Both are avid learners and value knowledge.
Dooku was noted to be an avid reader of ancient sith texts in Dark Rendevous. We also know that he was a well-respected jedi in the order due to all his knowledge and wisdom. We can also assume that he is a well-rounded person who takes joy in learning due to him assuming the role of head-of-state for the Confederacy of Independent Systems. His success at diplomacy and bringing various systems together towards one main goal requires a certain amount of skill, knowledge, and willingness towards learning that your average Joe would not possess.
Raven is seen reading throughout the series and is seen giving useful advice to the other titans on a variety of different topics in different scenarios. She has demonstrated her prowess as a well-rounded person.
Both she and Dooku take pride in learning and maintain knowledge and wisdom in a variety of areas.
I can add on to this later, but these are my main points.