Do you always use a tag ??

No, but when I start a new discussion I use tag with all new discussion if not none will find my discussions, but responding a discussions I do not use tag always. I use tag with response when I find it with my similar discussion so that other user can find my discussions along with this. So using tag is beneficial.

Not always - it depends. If there hasn't been a tag set, I'll put one in, but often I find that by the time I get to the discussion, anything I would have tagged it has already been said anyway.

Yes, I try to always put a tag in every response and discussion I start. It helps people find your discussions and you also get credit for them. The only time where I don't want to add tags is when I am commenting back and forth in a discussion and have already added several.

When I start a new discussion I always do but when responding I seem to slack off. I think it is better to tag because that way before starting a new discussion you can search to see if one has already been started on the topic of interest.

I do now although I didn't in the beginning. The tags help organize the discussions and make yours more visable in the long run.