95% of the time I'll do a lights and dark load separately. If I need a bunch of different colored items done, I will do all together in a Cold/Cold Setting without a problem.
For designer jeans or very dark items, I do a Cold/Cold setting using Woolite for Dark Colors. Hang dry the jeans and anything that is dryer safe goes on Perm Press, Low Heat.
For the colors, I use a Warm/Cold or Warm/Warm setting and I add the detergent, then turn on and let fill. At about half full, I then begin adding all of the clothing making sure that each piece is not scrunched up. A typical way I find if the cycle is full is when all is filled up, when you push down on the clothing, there should be some play between the clothes. It should NOT feel like 1 piece of clothing in there. Dry on medium heat.
Light colors I will do a Warm/Warm or Hot/Cold setting with a high or medium heat dry. Add everything as stated above.
As far as products, whatever is on sale for detergent. Purex has been the one lately. As stated above, Woolite For Dark Colors works great for dye sensitive materials. I will also add some Fabric Softener (Gain) in the Downy Ball to each load, then 2 Downy Dryer sheets per large load. In the light colors, I will add in 1/4 cup of bleach when I add the soap and let fill up most of the way before adding clothing to insure proper dilution. You can also substitute Oxy Clean (2 Scoops) with this.
Hope this helps.