Ned help with DILR preparation by doing sets

I'm not very weak in DILR, and I've already completed the theory/concept part. However, I'm still struggling to understand and solve DILR sets independently.

Can someone please suggest how I should structure my DILR preparation from here? I want to practice sets in a proper basic → intermediate → CAT level → advanced progression so that I gradually learn how to approach and crack different types of sets.

Also, which YouTube playlists or sources would you recommend for this? I'm specifically looking for CAT-level sets that actually help in developing set selection, approach, and problem-solving skills rather than just learning theory.

Any suggestions for a good playlist/resource and a practice strategy would be really helpful!