I have been processing a few rolls of Kodak Portra 400 over the last couple of weeks and the biggest thing I have learned is that what everyone says about getting the color right is true! Not to say you cannot get reasonably usable results but getting consistent color accuracy is a bit of a pain. The key really does seem to be temperature control. All you need is a good thermometer and patience.
I found that running tap water as hot as I could get it into a cooler with the bottles of C-41 chemicals in it and then letting the chemicals heat up in that cooler draining and repeating until I could get them to a high stable temperature provided the best results. If you can place your daylight developing tank in the hot water when your not inverting it or agitating I think you may have even better results. There are a few things you can do in camera to get the colors looking better.
The biggest thing you can do in camera is to do accurate metering. Sunny sixteen is great and all but to really get accurate colors you need to meter.(with your camera/phone/dedicated light meter) A color balance card could also help you dial in your photos. Remember you are probably not shooting film for color accuracy but you do want to get close.
This was a really fun day of shooting and if you want to see some more photos from this roll check it out here: https://flic.kr/s/aHsmpb9nCp