I did not pump just for the sake of pumping or building supply with my twins. A few days after coming home from the hospital, one son had to return for 48 hours. I pumped during that time so he could have breastmilk. But after that I only pumped when I wanted to be able to give breastmilk in a bottle which was not very often. I nursed A LOT in the first few weeks to build supply.
my EZ2 nurse breastfeeding pillow. I tried tandem nursing right away and preferred that for the first 6 months or so.
As you know from nursing one, it can feel like you are breastfeeding around the clock with a newborn. Well that is one area where I think it does feel like double the work with twins. Not truly double, but I did literally nurse around the clock. It is intense in the beginning so try to get as much support as you can. I have two older children so my dh was 'in charge' of them for the most part in the first weeks and my mom and sister came to give them attention too since I was so busy. My dh also kept me fed and hydrated.
I do think it is still easier than I imagine preparing formula and washing bottles for two must be. And just like with one infant, it does get easier as they get older. I am still nursing both my boys and they are 21 months. It sure is amazing to look down and see not only one set of eyes, but two looking back at you.