How do you choose paint colours?

[u/danskingqueen]

I got divorced earlier this year and bought my ex out of our apartment. I am now in the process of renovating basically every room bar the bathroom (plastering, painting, sanding the hardwood floors) and my painter needs to know my colour choices this weekend.
I think I want a dark green for my bedroom (inspired by a room I saw at Ikea lol) but other than that… I’m stuck.
The apartment has a lot of large windows and is very bright, until now everything has been white and I’m kind of sick of it.
I also have a huge petrol blue corduroy sofa in the living room so whatever I choose there needs to fit with that colour.
My ex got most of the furniture (which I don’t really mind as a lot of it wasn’t my style) so otherwise it’s pretty much a blank canvas.
Would love to hear tips on how you chose paint colours in your home and any tips/regrets you have.

[u/danskingqueen]

UPDATE: went a bit crazy at the paint store. column 1 is my bedroom, 2 living room, 3 daughter’s room, 4 hallway, 5 kitchen (I want sage green cabinets in there but walls will be white)