Optimize affiliate link
Suppose Christmas is coming, then in your blog place links to those products that you think people usually buy on Christmas. You can search for different products on Amazon or other sites and use that affiliate links in your blog.
Optimize posts for money
During the festival season, write review posts in your blog of products related to the festival. In this way, you can get a large number of affiliate sales.
Optimize posts for traffic
To get high traffic during the festival season you can start some sort of contest and giveaways on your blog/site. Doing this will also help you to get high traffic.
Optimize your blog theme
To leave a good impression on your readers you can change your blog theme/template for 2-3 days related to the festival. Like, if it's Christmas you can switch to a Christmas theme etc.
Optimize your blog for SEO
During the festival season, try writing on those topics that you think people with the search for more. Now, you will say if you have a tech blog how can you write on other topics. For this, you can create a new category on your blog called off-topics and can share off-topic articles there. Do read my article titled Write Off Topic Content And Get Traffic
Optimize hosting
If you expect high traffic during festival seasons then it is good to switch to a reliable hosting service with high bandwidth, space, and CPU usage.
I am sure by following the tips above you will surely benefit a lot from the upcoming festivals.