In my yeshiva, I've joined a b'iyun shiur that makes extensive use of a variety of rishonim. I find its hard to keep track of differences in the language of each specific rishon. What advice do you have for clarifying each rishon's approach, especially the Ramban?
In my personal experience, I find that the better I prepare the Gemara with Rashi, the easier it is to understand the Rishonim. If you know all the steps clearly and how they link together, it becomes much easier to follow the reasoning of the Rishonim. So often I would review a Gemara and Rashi four times or so until I felt I knew how all the steps connected according to Rashi. This also helps to separate where the links are obvious, and where there is room for interpretation. (An example of what this should look like when you are done is Rashbam on Bava Basra.)
Once you review the Rishonim, go back to the Gemara to make sure you know how they read it. I like to do the Rishonim in roughly chronological order (after Rashi, Tosafos, Maharsha), to keep track of who is responding to whom. This won't help for Ramban, who is famously harder to understand than other Rishonim, because of his terseness. For Ramban, it can be easier to skim it quickly to see what he addresses, then compare it to later, lengthier Rishonim that were heavily influenced by him: Rashba, Ritva and Ran. On many masechtos, the Chiddushei HaRan is almost like a lengthier version of Ramban, and can be very useful to understand what the Ramban means. But again, the most important thing is to make sure you know the gemara very well.
But finally, ultimately it just takes putting in the effort. Over time you'll find a method/system that works for you. Whatever method you take, there won't be a shortcut; just a system that you find reliable and self-correcting so you end up understanding the gemara correctly. To quote the famous Gemara:
וְאָמַר רַבִּי יִצְחָק אִם יֹאמַר לְךָ אָדָם יָגַעְתִּי וְלֹא מָצָאתִי אַל תַּאֲמֵן לֹא יָגַעְתִּי וּמָצָאתִי אַל תַּאֲמֵן יָגַעְתִּי וּמָצָאתִי תַּאֲמֵן Rabbi Yitzḥak said in the style of a previous passage: If a person says to you: I have labored and not found success, do not believe him. Similarly, if he says to you: I have not labored but nevertheless I have found success, do not believe him. If, however, he says to you: I have labored and I have found success, believe him.
I'll close with an actual description of learning gemara from the Ramban:
אבל עכשיו שנהגו לכתוב התלמוד אם השאילו מסכתא אינו [כן] שכל אדם שוין בו, והשונה פרקו מאה פעמים ומי שלא שנה אותו מעולם כלם נוגעין בהם ומשמשין בהם שאין לך אדם רגיל שלא יהא צריך עיון ומחשבה יתירא ולמשוך אילך ואילך ולגלול אותו מתחלתו לסופו ומסופו לתחלתו כדי לעין בהלכות הצריכות לו לאותה הלכה שהוא שונה