Emmet - mainly for the multiplication.

Small things like being able to just type in ul>li*5 rather than manually typing it out

When you are changing and updating your code update your comments/docs also, there's nothing worse than getting confused by someone else's code to find that the comments/docs are wrong

I don't understand how you see so many people talking shit about php and when you click their profile they are php developers

Now I'm no designer but I once had a client complain about the colour of his footer because it was grey and he didn't want grey he wanted "light black"

Previous Job I had finished a website for a client but the launch date was delayed (the logo was being redesigned) and when the client was ready to launch I was on holiday

Before I went I sent the files to my colleague and asked him to do the launch but spelt his email wrong

Never checked my emails on holiday so the client had to wait 2 weeks for his website to launch