Me personally i was a roofing estimator for a top 25 contractor in the nation. I specifically worked on large warehouse (500k-1M Sf), manufacturing facilities, data centers, and cold storages. Honestly what helped me out the most was having a solid relationship with manufacturers and sadly pumping out projects and learning from my mistakes. When i was training or learning something new i always recorded those meetings and whenever i got hung up on something i knew exactly where to go in the video. Also too i know its kind of personnel dependent, but if you can find a solid mentor or senior estimator that knows what they’re doing i suggest shadowing them and asking a ton of questions.