Specifically the easier to medium math questions, the first reading comp passage (assuming they go from easy to hard), and the sentence completions.
Why not just buy/borrow an SSAT/ISEE prep book. It’s always, IMO, better to prep for the test that you’re actually going to take.
The questions in the Kaplan and Princeton prep books don’t seem hard enough compared to the real tests available from SSAT and ISEE.
If you are stressed about what score you’ll get on the ISEE…