One mistake I'd add is trying to "write code first and debug later." Spending a minute to think through the logic before typing usually saves much more time.

A few habits that helped me understand Python better are:

• Test small pieces of code in isolation instead of writing an entire program at once.
• Use print() or a debugger to inspect variables and confirm your assumptions.
• Pay close attention to lists, dictionaries, and mutable objects, since unexpected modifications are a common source of bugs.
• Read the full error message instead of only looking at the last line. The traceback often points directly to the real issue.

I also think building small projects reinforces these concepts much better than solving isolated exercises. When you encounter the same mistake in a real project, the lesson tends to stick much longer.