In my physics classes in undergrad, we would get problems that would each take 15-20 minutes to solve. They were complicated, required knowledge of a pretty large and specific set of equations, and a fair amount of algebra/calculus in order to solve. Believe me when I tell you that the MCAT is nothing like that. For the most part, physics problems on the MCAT can be solved in a few steps, often relying on one core concept and 1-2 simple equations. The MCAT is more concerned with you being able to identify relationships between terms in an equation and will usually not expect you to actually perform extended computations for any given question.
2. Focus on broad concepts and relevant applications. Don't get bogged down by nitty gritty details.
A lot of prep books (Kaplan especially) liked to throw in equations and problems that are not at all necessary to know going into the exam. The MCAT wants to make sure you understand concepts outlined in the content list, not every single law/rule in your Giancoli physics textbook. For example, Kaplan spent a lot of time going over Kirchhoff's rules for solving complicated circuits despite it not being mentioned on the official content list. By doing so, they make it easy for you to overlook bigger and more important concepts that are much more likely to be tested and instead teach you rote/procedural problem solving that is much more relevant for a university course. Instead of knowing Kirchhoff's equations, know conceptually that the current through resistors in series is constant (conservation of charge, which is mentioned on the list) and that voltage across resistors in parallel is the same (conservation of energy).
3. Each time you learn a new equation, practice seeing how messing with one of the variables would affect the others.
The MCAT loves problems that ask you what happens to one variable when another variable changes. Recognize these relationships when you learn a new equation because it will reveal fundamental concepts. For example, for the Power equation for lens strength (P = 1/f, where f is the focal length of the lens in meters), it is evident that an increase in focal length decreases the refractive (bending power of a lens). Now you should ask yourself, what does a lens with a large focal length even look like? Does a it have a big curve or is it flat? Remember that the focal length is determined by creating an imaginary circle using the boundary of the lens, finding the radius of that circle, and dividing it by two. Now its evident that big focal length = flat lens. Why is any of this important? People with presbyopia (i.e. old people) have lenses that have crystallized and now have trouble bending. This means that their lenses have a big focal length...low refractive power...can't bend light well...image will converge too late (i.e. behind retina). How do we treat them? With converging (convex) lenses! Now we have made a full circle and have thrown in biological/medical applications. This is how the MCAT wants you to think.
4. Learn your units.
The MCAT will once in a while throw in a problem where you will be like ??? but is actually extremely simple to solve using dimensional analysis. For instance, Power (this time the rate of energy transfer) is measured in Watts. Watts is composed of a J/s (remember, work/time). A Joule is composed of a kg*m^2/s^2. Know how to break down everything into basic SI units.
5. Rely less on your intuition, more on empirical data/equations.
Throughout my experience as an MCAT tutor, I have seen a lot of my students make the mistake of relying too much on raw intuition in order to solve physics problems. Keep in mind that your intuition can betray you, especially when you are outside of the mechanics realm (and into electricity, magnetism, quantum, etc.) For instance, does the magnetic force (F = qv x B = qvBsin(theta)) do any work on a moving charge? Intuitively, it may seem like the answer is yes, but if you do the math you'll see it is no! Because the lorentz force is a cross product, by definition it must be perpendicular to the velocity of the charge. When a force is perpendicular to an objects displacement, no work is done (W = Fdcos(theta)).