There’s a lot of things that go into making great software, but one of the main things is consistency.
It’s not a very sexy topic to talk about as it seems so basic and obvious…but it’s one of the hardest things you can do and takes time and patience to do right.
Consistency should be everywhere in your software.
In your code. Variable, method and class names should be consistent and follow a naming convention. Tabs vs spaces. Capitalization. Location of files. Formatting styles.
In your design. Navigation should stay the same. Fonts. Text size. Color palettes. Layouts. Forms. Messages. Alerts. Popovers. Links.
In your words. Things should be phrased in the same way. Names for sections or actions should follow a rule. You shouldn’t use ‘delete’ on one screen and ‘remove’ on another.
For all of these things, it doesn’t matter what the thing is…but that it’s consistent. So it doesn’t matter if you use tabs or spaces, all that matters is that you use the same thing all over.