Common Challenges in MEP Estimation and How to Overcome Them

I'm an MEP estimator working to build my network, and I want to share my experience with this forum. In the beginning, I took a lot of time to calculate labor and material costs, and as a result, the budget was not enough and the project was behind schedule. Did you ever grapple with unforeseen costs that seem to come out of the blue?
To me, it was to utilize certain Construction Takeoff Services. The above-mentioned services assisted me in getting correct material counts and precise cost details which, as a direct result, reduced mistakes and resulted in more accurate estimates. I found the right tools to be safe.
Therefore, the budget was something I was able to stick to and expenses I could avoid. How do you deal with MEP estimating in your projects? Do you count on software, or do you use some other ways? I am eager to know your experiences and the tips you have had to know the time when you overcame their problems!