Part 3 of 3: Quick Rules for Mobile Design

Whenever I hear rules, I can’t help it, I want to break them. So I hesitate calling these rules. However, in our office, these are known as “Kat’s rules”


the actual touchable area must be 100 pixels by 100 pixels or larger. You can design it to be as small as you want, as long as the active button is 100 x 100.

Type size:

never smaller than 18pt.


Don’t use an arrow that means swipe on one page, but means tap on another page. Use icons and other visual cues to mean the same thing each time.

Landscape vs. Portrait:

First, pick one. Never create one app to be viewed in both, unless there is a good reason, and in that case, there better be different content in each orientation.

Consider the content before choosing the orientation. If you know you will be asking the user to open vertical PDFs or other documents, don’t make them turn back and forth. Create in portrait. If you will be using lots of horizontal videos, again, don’t ask the user to be flipping their device back and forth, create in landscape.


How will the phone or tablet be used? My thumb can only stretch so far comfortably. And if I will be using the tablet as a sales tool, don’t ask me to keep reaching across the screen to tap. Especially if the user will try to do that upside down. Consider buttons across the edges.

Test on the Device:

Whether you sideload or take screen shots of your designs in progress and email them to your phone or table, do this often. Designs look very different on your desktop.

Don’t add interactivity for the sake of interactivity.

Kat Topaz headshot

A firm believer that strong design drives readership, extends brands and just plain makes a difference, Kat Topaz has redesigned hundreds of publications nationwide and repositioned countless brands to huge critical, and financial success. At 6D, Kat applies those same principles to the mobile space, working closely with UX and UI teams to design for every type of mobile strategy. With Kat’s large network of clients and ability to attract top tier talent, design is not an afterthought at 6D. It’s a driving force in the mobile experiences we create.