I guess I could give you all kinds of technical tips.. The best thing to me, is making sure that you emote when you sing. I can't tell you how much of a difference that makes. I hear people just going through the motions and it sound pretty.. don't get me wrong, but it's just not very moving and doesn't connect well. Music is all about emotion and feeling and there are so many subtle nuances that can convey different messeges.. word stress, amount of breath in the tone, dynamics, accents, even how you SAY the words.. when you are aware of these things and make the most of them, it can really enhance your singing and take it to the next level..
On the technical side of things, tension in the voice is a biggie. All the work should be in the AIR, not your throat. The air should be where you get your power and where the notes come from. IF you feel yourself manipulating your sound in your throat (feels like you are squeezing) you need to relax the throat muscles and add more air and let IT do the work. Also your jaw and tongue can create a lot of tension... My husband is staring over my shoulder and wants to go to lunch
so i'll stop here.. i may come back and keep yacking later