Increasing the proportion of unstructured time alone is the key - as Glenn Gould once said:
I don't know what the effective ratio would be, but I've always had
some sort of intuition that for every hour you spend in the company of
other human beings, you need "x" number of hours alone. Now, what "x"
represents I don't really know; it might be two and seven-eighths or
seven and two-eighths, but it is a substantial ratio.
you may need to find whether you are an evening or a morning person - an
owl or a lark: I am a lark, so I get up at 05.00 hours and do my best
thinking/ creative stuff before 11.00. But most creatives are owls.
Thirdly - you need to get enough sleep of sufficiently high quality: a lot of creativity happens during sleep.
So the following need to be got right:
1. Unstructured time
2. Diurnal rhythm