The key to 21st-century banking is to be heavily into mobile, social and online channels. So if I were launching a new bank today, the first tenet would be to launch a differentiated, digital brand that is cool.

What does "cool" mean in banking? It means offering apps that are capable of personal financial management and that are simple to use online and on mobile devices. It means making digital channels securely cool by authenticating customers' identities using their geolocations and mobile signals. It means never asking customers for names, account numbers and passwords, instead simply giving them a personal space where their voices activate the services.

Banks can be cool by rewarding customers for their loyalty with gifts and goods such as airline miles and iTunes gift cards based on account usage. They can go even further by offering customers those rewards as they walk past a given store or Google a particular product. And most importantly, banks can be cool by relating to their customers. This means talking to customers as humans when they call and making them feel that they are really understood because their data has been understood.

Then, to give the bank gravitas, I would invest heavily in viral and mainstream marketing campaigns with a personality or personalities whom everyone would find relatable. The spokesperson would need to be someone people trust who is not easily bought. I would want a leading celebrity consumer champion—an Oprah Winfrey—whom I would convince of our cause. Having this type of personality on board in the advertising would be a coup, since someone like Oprah would only endorse the bank if she truly believed it was different and better.

With that as my starting point, I would then start thinking about how to organize the bank and its cultural approach.

The first thing my bank has to achieve, once it has its vision of operation, is to clearly define the customer. I would have no target client base except one: those who want to deal with a cool and fair bank through the mobile Internet. That would attract its own client profile.

The people who want to deal with a cool and fair bank through the mobile Internet have no predefined definitions. They may come from a range of demographics. I would then build very specific areas in the bank's mobile Internet channels of service that cater to diversity, and specifically target the needs of each demographic in a cool and fair way.

So what would my bank's customer be like? My bank's customer would want to be treated like a human. My marketing program would therefore focus on using social interaction online to attract viral amplification, and it would be transparent in its fees and approach.

My bank would build its processes based on the user experience people desire, and it would serve as an antidote to common bank practices that frustrate most people, such as lock-in fees, hidden charges, balloon payments on overdrafts and so on.

My new bank's motto would be "don't screw the customer", and I'd make it clear to clients how I would avoid doing that. My bank would support customers joining an online "screw loose lounge" where they could rant and rave and discuss and debate. There would be also be a "live and unscrewed" section for staff and management to air their hang-ups and thumbs ups.

All this would mean that I would have to hire cool and fair people who get the mobile Internet. So my hiring would be based on a tweet: "Do you want to work for a cool and fair bank?" Respondents would then be interviewed if they replied to my tweet, and would be vetted based on whether they smiled when they came through the door. They would also be vetted to see whether they picked up the $20 bill that I left on the floor in the corner as they came through the door. If they did, did they give it back?

I would aim to create a happy culture that in turn creates happy customers. I would also define "cool" in my own way. A cool bank is a bank that people want to be with, either as a customer or as a staff member. This bank would differentiate its brand based on being clearly interested in the customer, and by being responsive, modern, transparent and honest. In other words, a fair bank that gets the mobile Internet.

Don't get me wrong. None of the above suggestions are easy, simple or quick to implement. But it would be worth a try—wouldn't it?

Chris Skinner is an author, expert and speaker on banking, finance and fintech. This article is adapted from his latest book, Digital Bank. Follow him on Twitter @FSClub.