Fluid movement and micro interactions enhance the user experience. Little extras are better than making everything really flashy. Always label your icons for accessibility. Depth - adding distinct visual layers is never a bad thing.
Prototypes: Make your initial designs interactive. Understand UI and the structure that goes into them. Simple is better. Start with designing big and then scaling it down and making the idea more reasonable.
Principles of User Interfaces:
Format content, ease of use, touch controls - make using the app feel easy and natural. Some tasks need the full screen and some don't.
Text size: Make sure everything is balanced and fits appropriately. Distortion proportions. Keep it simple 3-4 colours.
What did I learn? / Reflection:
That being able to design well for everyone is important. Accessibilty>. Prototyping is important to make sure the project feels right. Also will save money in the real world.
Questions/Things to consider:
Usability testing. Test Often at all stages.
Consider the impact of colour contrast, user attention.