Following are some major tasks which I think will definitely help you.
1. Blog Posting
Only make sure you blog has interesting content, do proper research and then post.
2. FORUM and Article submission
Don't use bot software here, try to submit new content rather than copy pasted content. Google will definitely increases rank base on content.
3. Question and answers
It will help in gaining more traffic.
4. Image backlink
Image is more powerful than text, use new images provided by client.
5. Keyword Research and website Analysis
here keyword is the key tool and it greatly effect the ranking.
This just few tasks come under offpage seo, in SEO services company India following tasks performed.
Hope it helps you.