1. Find a good color palette
It’s 30% of the work
2. Use few colors
Or go monochrome altogether
3. Less pixels = less work for you
And more work for the viewer. Let them fill in the gaps.
4. Less polygons = less work for you
You don’t have a 100 person team behind you
5. Go flat
If you are not confident in your drawing and painting skills, avoid outlines, use geometric shapes, solid fills or simple gradients.
6. Put a filter on it
A shader or a 2d filter can add some depth to an otherwise simple style
7. The Internet is full of images
Photoshop, rotoscope, trace