Eight tasks on one company, Ashby Workwear, laid out like the Copperline model: income statement, balance sheet, cash flow statement and an assumptions block, with two forecast years.
Each task blanks out one part of an otherwise complete model, so you practice every link in turn: the top of the income statement, interest and taxes, working capital, cash from operations, investing and financing, and the balance sheet roll-forward. Task 7 hands you a model that doesn't balance. The last task blanks the whole cash flow statement and the balance sheet links, with a timer, the way a modeling test would.
Two habits help. Build each block in order, top to bottom. And when a check is off, use the size of the gap: one line missing, or twice a line with its sign flipped.