I completed all the Yoreh Yoreh exams within two and a half years,
with good grades (an average of 80). I don't have a phenomenal memory. Even so, my advantage was that I implemented a few methods:

1. Initial study — do it however you think is right. From the original sources, from summaries, in-depth or broad survey study, each person according to his framework, his value system (regarding "how one should study Torah," etc.), and above all, your time. (In my opinion, quick study from good summaries can save about 90% of the time compared to studying the original sources.)

The main thing is to do one or two rounds on all the material, just to get acquainted with it. A cognitive process in which the material goes through processing and understanding of the opinions and reasoning. (There's no need to memorize, or to know how to quote, etc.)

2. Still, I'll give an insight for someone doing initial study from the original sources. Starting from the Tur and the Shulchan Arukh.
Since the material is scattered across several books and decisors (from the Talmud to the Shakh, passing through the Magen Avraham, etc.), I noticed that the main difficulty and time are devoted to framing and organizing the opinions — finding the connections, who disagrees with whom, and so on.

The solution: read a summary by someone who already did that exhausting work. Learn each topic as a single "unit" (Talmud, medieval authorities, halakhic ruling, and so on) from the summary; that's how summaries are built. Then afterward approach the Tur itself.
After each section/topic read from the summary — study it in the original source.
The material will fly.
Win-win. Both in the original sources and also fast and easy to absorb.

3. After the initial study comes the stage of remembering the material.
At this stage, it's recommended to take that same summary from the initial study and review it repeatedly. Go over it once, twice, three times, depending on the time.
Most importantly: get to a point where you know the material on the level of knowing where every topic is located and framed in the summary.
Toward the most important stage in the process.

4. One month to three months before the exam (depending on the material — from Sabbath to mourning laws),
go into the Rabbinate portal, print out all the exams there are (about 20-30 exams from previous years), and study this way:
Start with the earlier exams and move toward the newer, harder ones.
Read a question and… answer it from inside the material, meaning: from the summary.
Don't try to answer on your own — that will cause details to be omitted.
Don't write — that will slow down the studying.
Answer the response in your head,
and move on to the next question…
Answer all the questions from all the years this way.

In my opinion, this is the most important part of the process.
The questions over the years:
1. Are challenging, difficult.
2. "Hit the soft underbelly" of the material. Meaning: they focus on the important topics. For example: in the laws of Sabbath — more on the laws of cooking and less on the medical practices brought by the Shulchan Arukh.
3. Open a window onto many details and topics that were missed in the initial study.
And most importantly:
4. This form of review is not built around covering ground, and there's no pressure of: to stop by the end of the day, by the end of the siman, etc., which creates pressure and skipping over important topics.
Rather, the task is: each question on its own. There's no pressure to stop.
This is an insight based on advice from educational psychologists.

5. It builds a hierarchy. When you study this way, in practice you focus and review countless times the topics that are likely to be on the exam, and less so the ones that aren't.
The questions on all the exams repeat themselves; if not in the exact same wording, then in the same topics.

For example: in the laws of Sabbath, if you study this way, in practice you've learned the laws of cooking 15 times, and the laws based on irrelevant medical practices once, if at all.
The chance of a question on cooking is 40%; the chance of a question on medicine is 1%.

Coming to the exam with this background creates a situation where you're able to guess which topics will be asked on the exam.
In addition, you know them, because you spent the last month reviewing only them.

Recommended summaries: for Chupah and Kiddushin laws — Heikhal Shlomo.
For the laws of prohibited and permitted foods and niddah = Tamtzit (phone number to obtain it: 0527159662). It's written well and briefly. But you need to add the Talmudic passages yourself.
Sabbath — I don't know. You'll need to look.
In general, Heikhal Shlomo is okay for everything.