How do you train your sales reps to "tune in" to the buyer?

I agree to everything Dale and Ryan already mentioned. I'd like to add some thoughts around these skills:

Make sure in trainings and coachings that sales reps really understand the current challenges based on changed buying behaviors. On a very high level that's:
Sell higher and cross sell!
Both challenges have a lot to do with the sales reps' comfort zones and both challenges require a lot of training and coaching - not necessarily on what to sell but on how to sell and to whom. Creating these awareness is often key to success because people will have to work on their selling behavior and who likes to change behaviors when it's not clearly defined from what into what...

Sales reps need to develop a deep understanding where their customers are in their buying process respectively their problem solving process and how they can use the above mentioned conversation skills. Additionally they need to get a better understanding of the customers roles and responsibilities and they need to understand the key challenges in the customer's industry related to these roles and responsibilities. That means teach them to figure out who the customer really is for a specific solution or service offering. Is that a business leader, the CIO, IT managers, procurement managers? And it means to figure out how the agreement network at the customer looks like: who are the roles that have to say "yes" to get a decision?
That all these challenges have a huge, huge impact on the collateral sales reps need, should be part of another question...

As you may have different types of sales reps to support (some are more focused on products or on processes, others are focused on figures or on networking etc.) you could use different training and (on-site) coaching methods to make people aware of these challenges and to teach them to develop their skills and to grow. Combinations of creating awareness, specific role plays and usage of the so-called “tribal knowledge” of excellent A reps could be relevant training and coaching elements.

I think Tamara hit a key point by mentioning that it is crucial for sales people to understand where the customer is in the buying cycle and to know the role and motivations of the people involved in the buying team.

This implies that salespeople are able to ask relevant question to find answers to these topics.

These are prerequisites for salespeople to be able to hold conversation which are meaningful and value adding to the customer. It is these conversations that will create the impression of a sales person who is "tuned in".

What this means though, that salespeople have to forget the traditional "sales pitch". Any training spent on this aspect is wasted effort. Spending the freed up time on things as Tamara suggest are far more productive.

Wouldn't "tuning in" be a selection criteria for getting hired?

Craig,
You have hit upon the keystone sales skill. Everything else is built on this competency. Sales people can be trained to ask better questions and to listen more constructively. It takes an understanding of the power of a better sales question, some time spent developing the skill and then coaching for implementation. So, in other words: training plus coaching = better execution. You may want to review one of my books, Question Your Way to Sales Success.

In addition to the answers above, it is important for the sales person to be aware of the environment that the buyer is working in. This could be everything from the buildings, the office space, the reception area, the meeting rooms, etc... All of these environmental factors can tell you a lot about the type of type of organisation that you are dealing with.

In addition, it pays to understand where the buyer sits in their own organisation, who their boss is, what his/her needs are and what the bosses needs are.

Having a sales person who is able to pick up on the multiple small factors that influence the buyer, and being able to adapt to these factors, will ensure you have a "well tuned" sales process.

When I had sales meetings with my teams I would at least once a quarter bring in a buyer/decision maker panel of people they were not seeling to. The panel would discuss buyer habits and processes,why they did busdiness with one person vs another. This roundtable with a Q and A format worked wonders. I brought in large companies,mid size and smaller ones to keep a good mix. Then in follow up meetings and during ride alongs we would discyss on an individual basis some of the thoughts from these sessions.