Besides experience, I would also recommend learning your tools well. Game engines, IDEs and drawing programs provide many shortcuts and tools that would help you create things faster. A good habit to develop is to be mindful of things that take you a long time to do, and search google (or chatGPT) if there's a shortcut for them.
For example, most IDEs would let you jump to a file by typing it's name instead of having to search for it in the files tree and click on it with a mouse. This is a HUGE time saver.