Reuse code, if you repeating on 2 or more places consider put that inside a function and call it everywhere you need that code. Application resources consume. For example you have a variable that will have values between 0 and 20, declare it as byte instead of int. Byte support number until 256 and only consume 1 byte, int support a number until 2.147.483.647 but consumes 4 bytes. If you are loading a list of objects this can have a huge impact on performance. Comment code, give some hints of what you have done. When you have maintain code not developed by you, you will understand the importance of comment code.