@Faraad Mohamed I tend to always use Kelly Moore "Wise Owl" mixed down to 50% in an Eggshell finish for the walls, and just Behr flat ceiling paint because it looks good and is cheap. If you look at the pics above, the walls were painted with the 50% Wise Owl I am mentioning here. I like this color because it looks really good with warm tones, but it also looks pretty good with the gray tones as well. In the kitchen above, the counters are gray quart and the backsplash has gray grout, but the 50% Wise Owl looks great!
I do go expensive on the baseboard and trim. I use Kelly Moore Durapoxy in semi-gloss, and the color is Swiss Coffee. I also use the Durapoxy to paint doors and cabinets if they are being painted. It is an exceptional paint, but can be a little hard to get off your clothes or floor once it dries, so do your clean up quickly!
Here in Northern, CA, I have found getting a business account at Kelly Moore is pretty easy as a flipper, and it gives me a good discount on the price. I hope that helps :-)