I've never thought about it bc it's always been the MO, but good questions and my answers:
What does value mean to you?
As a service based business, making the client's life easier
How do you know what your customer will value?
I don't know going into a job but on the spot I just do a little extra to take care of something that I know would bug me if I left it unaddressed. I'm not unique so I know if the work looks like shit and bugs me then it will usually bug the client. And they paid for professional work so it's our obligation to do a professional job.
So in general customer's value making life easier.... i.e. yesterday I completed my scope of work but saw what the client had left to do DIY to meet a tight deadline. Before leaving I did 10min extra labor for free of something I do all the time that what would've taken him 2hrs his first time trying and he was already fed up with the laborer's before me. It's just being empathetic at the end of the day
What are someways that you add value to your work?
Being transparent and honest about the services the client chooses
Under promise timelines and over deliver
Leave the space cleaner than the way you found it
Communicate with the client promptly
Honestly if you do those 4 things you're ahead of 99% of contractors and automatically more valuable