1. go to sleep on an argument - trust me when I say this is never a good idea, you don't sleep well and the whole thing hits you twice as hard when you wake up in the morning and remember what happened the night before. Which leads me quite nicely onto...
2. regret the past - regretting the way you acted/the things you said in your past is futile, it cannot be changed (unless of course you have a nifty time machine in which case why would you be sitting around regretting things anyway?)
3. worry about the future - a tricky one I know, but again it's pretty pointless. If you're worrying about something you can control/change or act towards/against then do what you can and have faith it will turn out for the best whichever way it goes.... if you can't do anything then *shrugs* worrying about it isn't going to change or solve anything
4. ignore your intuition - gut instinct/intuition/psychic sense, whatever you want to call it we all have it to some degree and I have learnt from personal experience to never ignore it... all of the worst decisions and mistakes I have made have been down to me not listening to it, and while I don't regret my decisions, as they made me who I am, I do accept that I could have saved a lot of energy and worrying had I just taken heed of it's wisdom
5. forget to tell the people you care about that you love them - never, ever, ever do this as you never know when you'll be unable to tell or show them again. Things change so quickly in life, love is precious and is there to be shared.