While you can scale the size and scope of your capabilities up and down to match the needs of your client, you can't really scale the quality of the work depending on the client. Trying to scale your effort has long term implications.
We all have that extra gear we jump into when The Important Project lands on our desk, and the result is hopefully our best possible work.
But then what is our "regular" work? Just "regular"? What percentage of your work is "Regular"?
The hardest part of doing your best work all the time is that you have to fight human nature- we are hard wired to give the effort we perceive each job deserves. While that skill has served us well in the past, it can color how you are perceived by coworkers and clients in ways that nobody likes.
Reduce the amount of regular in your day.