One of the biggest time savers in my mortgage business was learning how to underwrite the most complicated scenario first.
If a client was refinancing their home to buy two rental properties, I'd underwrite the final rental purchase first, assuming everything else was already in place.
If that scenario worked, the rest of the file was usually much easier to navigate.
Instead of working through each step individually, start with the hardest part of the file.
It'll save you time and help you identify the right lending strategy much faster.