Hub genration is a closley guarded secret. However there are many hubs and forums on the subject. I will nutshell it here for you.
1. Participate - Publish hubs on a regular basis. An Answer questions and participate in forums.
2. Focus on Quality - It is not enough to particiapte but you have to do so in a quality way. For example, publish qaulity hubs that are well written and researched. Make sure your check for spelling and gramatical errors. The ore quality hubs you produce the more clicks you get and more "vote-ups" you get resulting in a higher hubscore!!
3. Hub Hop and spend some time reading the other hubs. It is a great way to participate because hopping leads to commenting. Commenting leads to questions and questions lead to hubs.
For what I have read if you have a hubscore in the high eighties and up you are doing pretty well.
Check out the forums and do a hub search on this topic. There are some great hubs on this. I have a good one for new writers as well if you check out my profile!!