Well, I have to say that I am pleased and grateful for the way the internship application process was handled at my grad school. Briefly, we are a clinical PhD program with a balance between research and clinical emphasis (CBT-oriented) primarily in medical settings. My program operates with rather strict vetting prior to being allowed to apply for internship. Students have to successfully propose by the end of June in the summer before they intend to apply and have to have completed all required coursework. Also, the student has to have obtained clearance from what we call their Graduate Studies Committee (GSC- 3 or more psychologists who guide and track their progress through the program). Once a person is cleared to apply, our program also checks with their dissertation chair in January (right before interviews) to see if they are on track to either defend before internship or to leave with minimal work left to do (e.g. data is collected and/or analyzed at the very least). If not, the GSC can outright deny the student clearance to register for internship credits during the next year (basically withdrawing them from the MATCH). This has not happened as far as I know, but I know this clause exists in our program training manual.
As far as prep, the outgoing class from the previous summer holds an info meeting and pass along our prep materials and even samples of our AAPI packet. We have 2 clinical supervisors (typically the training director at our affiliated VA and 1 other) who host regular prep meetings with clear benchmarks (finalizing site list by one meeting, 1st draft of essays by another, prep for interviews later, etc.) from August-December. Also there is one big meeting with the TD sometime around September to discuss general issues.
Overall, I feel fortunate to have had this level of support-- esp. as I have talked with others in my current intern cohort, here at SDN, and beyond whose programs take very different approaches.