1. Have a Consistent and Standardized UI: Keep the interface constant and use standardized elements.
2. Guide the user: Make clear where to click to progress. If one action is more important that other, have the button or action area for it prominently displayed.
3. Make (Call-to-Action) Interactive Objects Obvious: Make click and tap targets as large as possible, make the interactive objects big and obvious. Make the interactive objects noticeably bigger than the surrounding elements.
4. Give Feedback - Both for User's Interacting and Progressing: Give visual feedback then a user's interacting, as well as the user's progress if applicable.
5. Never Have Users Repeat Anything & Keep Signup Info to a Minimum: Ask for any info only once.
6. Always Have Default Values in Fields and Forms: Having a simple default value in a text field will push the user in the right direction as to what they need to type in.
7. Explain How the Inputted Info Will Be Used: Make it clear, comfortable and affirming as possible for the users how the info will be used ("Your email will be your login username", "Your location will be used to *do something*")
8. Don't Have any Reset or Mass-Delete Buttons: There's almost no situation where a user will have to wipe every scrap of data and start again.
9. Have Clear and Explanatory Error & Success Messages: Instead of "Oops, something went wrong" message that doesn't inspire confidence, have something more specific and explanatory like "Our database which holds your account info is temporarily inaccessible and will be back shortly".
10. Include a Clear Visual Hierarchy and Navigation (Breadcrumbs): Make sure your layout and navigation is very clear. Have clear 'breadcrumbs' at the top of the page.