There's some good tips there. Essentially focus on positivity and don't get bogged down in negativity. I find particularly that being negative about things that ultimately don't have much to do with you, is really pointless. Just removing those negative thoughts can help your state of mind immensely. I also like your tip for a positive greeting to others. It's such an easy way to be positive, and as you say, you almost always get a nice reward in return. It's win-win! :)