Broadbanding is a state of being on the look out - to make sure it's safe. As with focussed sensing it's also a state of alertness, but it's purposefully and actively, not getting on with life, just being aware of it.
Humans have no natural predators. Humans lack the motivation to go broadband. It may be useful to start with, to listen out for any dangerous pidgeons ...
There are many different degrees and qualities of broadband seeiing and listening, just as there are with focussed seeing and listening.
Start with Listening
With listening, everyone seems to have at least some idea of how to try and do it ... with seeing most people have no idea. This maybe because with seeing we are trained to focus with the eyes from such an early age. So i recommend starting with listening, it is far easier, and essentially practices the same thing.
SWITCHING IT ON
The ability to switch it on is the first step.
As a balance for focussed activity, animals often only do it for a second. Look at any pidgeon or blackbird while eating. This form of sensing is so vital for survival that they interrupt any delicious meal to do it. Notice how quickly they can change between doing what they want to do in their focussed mode, to their broadband mode - and the second the head is up, they are able to instantly turn off any self centered thought or behaviour and register if anything dangerous is moving.
I feel, especially to start with, humans - who are so out of practice - should do it for at least ten seconds to a half minute, at a time. Once you can do it, then you're welcome to do it hours long, but the ability to switch it on is the first important step.
A minute a day, might be a good idea for some people. - If you want to make it a priority, then do it whenever you think about it, several times a day.
There are lots of reasons for starting with these short periods. Partly because if doing this - even trying to do this - is enjoyable, then you will want to repeat it. Partly to create a feeling of urgency - it's got to be done now, and in a minutes time it'll be too late. And partly, to realise that you can turn it on, any time, without doing anything to prepare for it.
Your subconscious knows how it feels to use the senses like this. A minute a day which is interesting or enjoyable is the best way to give your subconscious the signal that it's time to remember.
Please continue with Listening