Avoid deleting in favour of editing, finding sources, re-arranging etc. We want Wikipedia to grow and improve.
Sign your messages on talk pages with four tildes (~~~~).
It's what the pros do, and what the noobs should do. But everyone forgets, so sooner or later SineBot will pick up your slack and write on your discussion page. You can also get a tool to help you not forget, it blinks or adds a button or something.
Get wikipedia tools! Goto your user page and add them to your /monobook.js.
This is the javascript that is executed on every page, you can put things here to change the way you (and only you - well only people using your account) interact with Wikipedia. You will need to bypass cache to have it come into effect though.
Learn to argue your opinion and not just argue and get involved with AfD and RfA (in order to practice this and to start to learn Wikipedia policies and guidelines).