A majority of the time you spend coding is to fix problems, to correct flaws in logic, or to fine-tune. When making such adjustments, avoid the temptation to make three or four changes at one time. Address issues one at a time.
The reason for the admonition is that it’s tempting to hop around your code and work on several things at a time. For example: You need to fix the spacing in a printf() statement’s output, adjust a loop, and set a new maximum value. Do those things one at a time!
When you attempt to do several things at a time, you can screw up. But which thing did you goof up? You have to go back and check everything, including the related statements and functions, to ensure they work. During situations like these, you will seriously wish for a time machine. Instead, just work on your code a little bit at a time.