Code structure and linting
When it comes to removing errors within an application, the earlier you can do this the better. One of the most useful tools for assisting a developer in doing this is to use a linter to help in reviewing your code to make suggestions around common bad practices or issues. For Apex developers, the open source Apex PMD library is my go-to tool to use for this and has a community created plugin for Visual Studio Code available to allow it to integrate nicely with the SFDX plugins for Visual Studio Code.
The use of a linter such as Apex PMD will allow you to catch common errors and enforce best practices in your code, and is particularly useful in a team setting to provide a baseline of agreed standards. Many deployment tools also include it as a step prior to deployment between environments to help verify the quality of the code being deployed before deploying it.
I have found a linting tool to be a helpful way of nudging myself and others in a development...