The best way to check your model is to print it out and check if there are any errors. It may be overwhelming to look over a model you worked on very long on a screen and printing it out, will make it easier to synthesize the information. As well, you can put in formulas to automatically get balance sheet checks, ways to break down EBITDA to UFCF and of course compared to street consensus and previous models. As well, another great way is to re-create the model off muscle memory in a simplified manner. If you are able to get a value in the same ball-park as your original model, you can be confident that it is strong and aligned with assumptions.