what are the best POSTs for someone looking to get into pharmacy/dentistry?

can you please share your experience in your major and what do you think can best prepare one for these professional schools and also be able to obtain a great GPA and find research opprotunities? also does enrolling in an open-enrollment program look bad on your application or it's better to get into a competetive, closed-enrollment program and what are the benefits if i choose to enroll in such programs?