Add a blog and videos....

improve your contents, increase the quality

Website design is the most important factor to reduce bounce rate. Website design should be user friendly and website load time is also important factor in this.

To decrease the bounce rate you need to understand the bounce rate and actually what it is then understand the reason for bounce rate. The definition of bounce rate means the visitors visit to your website and visit to your webpage and leave without taking an action just visit to your website and get out from your website with out any activity. To decrease the bounce rate you need to create the good page for your website so that the users can get the relevant information from your site.

quality contents an write article that very usefull for the reader

I think it depends on what your site is doing/selling. A high bounce rate does not necessarily mean you have a problem, or that Google will penalise you for it.

No Plagiyarism issues
Good Backlinks
Good Loading Time
More Images with alt tags

In the following way you can decrease your bounce rate of your website there are improve your content readability,avoid popup,keep the blog with fresh content,target the keyword with high value traffic,speedup page load time

Post relevant content to the user is the best way to reduce the bounce rate of the site..

Adjust the bounce rate of your website.
Reduce the bounce rate of the web pages in the Profit Index.

To decrease bounce rate of website, you must do, create attractive website with images and website content should be relevant content and should be easy to read.

Website proper layout with better internal linking will reduce bounce rate.

Have relevant content and more importantly, have interesting content!

How much bounce rate are you getting? And also, is it an ecommerce site or not?
Anyway, to decrease the bounce rate on your site first you need to see which page/s of your site receive the highest bounce rate. Analyze that site page and improve its overall functionality, maybe it Is not loading fast or properly, or some buttons not functioning etc. in short, improve and update that certain page. Then observe for a month if the bounce rate decrease.

I think it depends on what your site is doing/selling. A high bounce rate does not necessarily mean you have a problem, or that Google will penalise you for it. You might just be answering the site visitors question with your landing page content.