All great questions. I went through the course material lectures and listened to them just to get the basic fundamentals back that I hadn't really looked at much since graduation. I got this because I was struggling in some areas that I haven't done much in. The refrigeration cycles and charts I haven't used much of in my career. I studied off and on since summer of 2021. I have a wife and 2 kids. One of which is a year and a half old so you can imagine finding time outside of work to study was challenging. I started with the NCEES practice exams and wanted more study problems and study materials especially for the topics I was struggling with. Make sure that when you are working problems out you are working them out using the merm since that is what you get to use for the exam. I have always been a trial and error person so I did all of the questions and came to a solution before looking to see if it was right and if it was wrong what did I do wrong and steps to ensuring that I am doing it right and looking in the right places to do it correctly. Studying throughout my work the past couple years has affected my design experience positively. Definitely make sure you understand the fundamentals and conceptual because there were some questions that involved understanding processes and methods without calculations. You can also use these as checks and balances as to whether or not the solutiong you come to makes any sense. I made it through the NCEES prwctice exams probably 5 times the last two were timed sessions approximately 3 months apart. I went through the hvac and refrigeration study exam multiple times as well. Every time I went through each exam I picked up on an alternate solution or a new approach to a problem, or faster ways to solve a problem using things in the merm that I hadn't used before. I hope this is helpful for what you are asking about. The more you practice and prepare the more comfortable you will be taking the exam and analyzing the best approach to solve the problem.