I think it took me about 4-5 days (5 hours each) to get cooking to 60. Of course, I just burned through money and didn't sell anything, but hey... I got there.
THIS IS YOUR FRIEND. CLICKY CLICKY CLICKY.
Put in the crystal, cap, and your current skill calculate and keep it current to the day. It will tell you which way to face and all that to keep everything in the "2-4 The Prime Skill up zone". If you can do that you will skill up with blazing speed. This involves skipping days, jumping recipes, and facing certain directions, but in the end, you can net amazing skill ups.
Seriously, I took Alchemy to 6 in less than 20 minutes. I know its low level and all, but tweaking your skillups to be in the right zone makes it amazing.