I introduced the following coding conventions in my team a while back. I hope it helps you too:

1. All symbols (function names, variables, constants) must be in camel case.

2. Use meaningful symbol names and never abbreviate them. Think from the code reviewer’s perspective, they do not know your intention.

3. Consistently use same identifier for the same object or an object that refers to the same thing conceptually.

4. Never introduce any unused identifiers. Declaring a constant or function in hope that it will be used in future is a serious bad practice.

5. Avoid long horizontal lines. It is easier for humans to read blocks of lines that are horizontally short and vertically long.

6. Avoid single use variables as much as possible. In general for a reviewer/reader, complexity of code increases with no. of variables.

7. Capitalize SQL special words and function names to distinguish them from table and column names.

8. Do not litter the self-explanatory sections of code with comments. Only include comments to:
A. Explain business rules, domain-specific logic, or regulatory requirements if you think it is complex enough.

B. Clarify how your code handles edge cases or exceptional scenarios. This too is rarely required.

C. Document workarounds due to limitations or external dependencies. Prefer a special prefix like ‘NOTE’ for these comments.