Anyone have tips to study for the Sudoku test on the assessment?

I bought the Cut-E prep and on Medium difficulty on the 5x5 grid I can do maybe 6ish problems before the time is up. On hard I can do 2 sometimes 3 or 4 depending on the pattern. Someone was saying that the real test is harder than the "hard" setting on Cut-E, so I'm slightly worried about it. I've just been running through practice tests so far. I'm thinking about doing that for a few days and will take the assessment this weekend before it expires.