If you're looking to raise your hub author score (the little number inside your avatar box) above 75 then here's what you need to do.
First, you need to write some hubs. I recommend at least 10. These must all contain unique material (not copied from anywhere else) and cannot contain spam, gambling info, or pornography.
In each of those first 10 hubs you will write around 1000 words split between at least four text boxes, you will add a picture, and maybe a video from youtube (both must be directly related to your hub).
From there, you insert a link or two (no more) into each hub linking to other hubs you have written that are related, and then you wait ... go off to the forum and babble, answer questions (such as these), become visible in the community.
Within a few weeks your score will bubble up to 75 and beyond, provided you have picked topics for your hubs which are well written and are of interest to others.
And how do I know this? That's how I did it, so I'm relating a path that I already know works, and it will work for anyone else.
Also, there are many other ways to do this (as others will say) but I think this method is the easiest, as it covers all the bases and won't exhaust you in the process.
Good luck! We look forward to seeing those hubs. :)