Free themes and giveaways can attract followers, ratings and get you started in the theme business
Shopify Theme and Shopify Partner Program
Shopify allows you to take a cut from retail store subscriptions and sell your themes. You can fetch up to $120 - $2000 dollars.
Tumblr Custom ThemesGet inspired by Tumblr themes here https://www.tumblr.com/themes/
Get educated and get inspired. Tumblr themes go up to $49 dollars and more.
Know your artists
Animators and manga artists are thriving on Tumblr. If you were to monetize on tumblr, make sure you know your audience. Here's an example of an artist blog on Tumblr http://tzysk.tumblr.com/ Here''s another thousandskies.tumblr.com
What's a beginner friendly tutorial for getting started with theme development on Tumblr?
Apparently General Assembly Dash has a Tumblr Theme project. It guides you throw basic HTML and CSS and essentially that's what you need to get started. It will walk you through creating a basic bubble shaped profile picture and an input field to collect email addresses.
Amazon supports native ads on Tumblr
Technically Amazon supports banner displays and CPM ads on Tumblr but implementing it on the Tumblr side is a different issue all together. Pay attention Tumblr community guidelines and term of services is always the way to go.
Take Advantage of the Build-in Viral Factors
As someone who has done a lot of social media and content marketing, I think Tumblr has the most re-sharable form of blog posts. It's almost as instant as Favoriting a post. The newcomer with this prowess is Medium. Customize themes should not hinder this experience. In fact, it should highlight social shares and showcase them.