A few years ago I started creating small projects and began writing them up as Chasing Telescopes blog posts. The intent was to demonstrate what can can be created with just a handful of coding tools in your kit. Creating projects (no matter how small) is an excellent way to learn a new programming language, implement a new library or package, and to get your hands dirty with tools you are not familiar with. It's also a great way explore various data analysis techniques, and data visualisation tools. I’m also a fan on using ready-to-use web tools. These can be really useful for outreach projects, or when I want to get something visual up and running fairly quickly, and don’t necessarily want (or need) to build it from scratch.
Data Visualisation Projects
Exploratory Data Analysis » Interactive Visualisation » Science Communication » Astrophysics in a Data Science Context »
Machine Learning Projects
Exploratory Data Analysis » Creative Machine Learning
Science Communication » Citizen Science Projects » #dotastro Experiments