1) Mark optional fields rather than required ones
2) Use in-line form validation
3) Use smart defaults
4) Top- or right-align your labels
5) De-clutter your forms with information popups
6) Be clear about what you’re going to do with the information you ask for
7) Don’t make users remember yet another username
8) Let people know what stage of the form-filling process they’re at
9) Test your CAPTCHAS
10) Make your CTAs clear
11) Format your payment details fields so they're the same as they appear on a customer’s card
12) Set the delivery address as default billing address
"Research shows that when making a choice from a large range, performing physical acts of closure (shutting a menu after choosing, for example) that imply a final decision can increase satisfaction with that product. These are actions that give us confidence to “seal the deal”, as it were."
"Its mobile coupon-clipping app, Cartwheel, is a runaway success, data show: the amount of time shoppers spent browsing and shopping Target via mobile devices rose 251% in March to nearly 100,000,000 hours compared to a year earlier, according to comScore, and Cartwheel, primarily used in-store to help shoppers get deals, was behind all of that jump."