Modeling at work vs modeling tests

Hey all, I work at a large multinational real estate investment firm and we have very well built out templates for the investments we focus on. The template model is fairly large and complex but I've come to understand it quite well over the past few months that I've been in the role. When modeling, I am usually not modeling from scratch. Rather, we are using the template and making adjustments / adding in functionality where needed. However, for modeling tests, I've noticed your expected to be able to complete a model from a blank excel file with no guidance or resources to glance at. For those who are analysts and have 1-2 YOE and are looking to make the transition, how did you prep for the tests? I don't feel as if my day job has prepared me well to absolutely murder these tests. Instead, I've come to understand our model very well, can work it in very easily, and have learned a lot about other key areas (JV's, loan docs, mitigating risk, etc). Modeling on the job is fairly different than opening up a blank excel sheet and putting something together in a few hours. If I had a modeling test that I was to complete over 2-3 days, I would easily pass. If I had to complete something in 2-4 hours, I am not as confident in my ability to knock it all out without any references, etc. I’m very familiar with excel and all of the main functions needed to complete a model.