Guess what? Your mind still works even when it's doing nothing. The reason great ideas come to you in the shower is that your brain's bored and relaxed.
If you want to shake out even more ideas, therefore, it behooves you to disconnect more often. Instead of wasting cognitive energy at screens, just sit there with no stimulation other than a pen and pad.
Author Neil Gaiman says the only inspiration you need to write a book is absolute boredom. You'll be amazed at how the ideas start to connect when you decide to do nothing, unmoored from the stickiness of technology.
Taking your foot off the gas in the pursuit of dullness takes deliberate practice. You've been trained to do a lot more with continuous partial attention, but at the cost of engaging deeply on one particular task.
Busyness often gets confused with checking email, swiping left and right, and other screen-obsessed habits that never let you get out of your own head. Once you're more mindful of how you spend your waking time, you'll start to appreciate moments of boredom. Magic happens in an “unexpected state.”