I got a nice comment from Matt-Williamson. I also agree with it. You can follow it. I think, it will help you.
"To increase your Domain and Page Authority you need to increase links to your website and in particular your homepage if you want to increase that specifically. To do this you need to think how can you create some decent content that is link worthy and then you need to make sure it gains exposure so that it will start to gain links. There are lots of ways that you can increase your link profile using things such as:
- In depth product reviews,
- A blog (consider encouraging and rewarding guest bloggers that are authorities in your niche as they will have a strong, relevant following),
- How to videos in relation to your products and how they might come in when carrying out a task for instance,
- Content curation is also an idea (some decent articles on this on SEOMoz).
Now for the exposure; best place to start is to build up your social networks and start to interact and form relationships with people that are likely to have an interest in your products, in particular those that are authorities in your niche/product area. Then when you have built relationships with them you can expose them to your new content, which will then hopefully get passed on to their social following and through this you will start to gain links and more attention slowly establishing yourself as an authority in the process - win win situation!
If you do this and work hard at it your DA and PA will increase as you want it to. Just remember that when you are building links in a post penguin world don't over do the anchor text and always go for quality links over quantity, don't start using dangerous methods, such as forum signature and blog comments. Hope this helps - Good Luck!" Beside I will say, you can try this small strategy, Cause i am using this strategy, it helped me for increasing Both point.
1. Comment on Relevant Authority Blogs
2. Update Your Blog Regularly
3. Increase Indexed Pages 4. Increase Backlinks
5. Increase social signal.