I think Samwise said it best

Step 1: Assemble Your Ingredients

Feel free to scale portions according to your needs. This batch make enough for 8-10 people.

5 lbs russet potatoes
8 oz sour cream
1 cup of shredded parmesan cheese
1 stick of butter
garlic powder to taste

optional
half and half (if your taters are not smooth enough)

if you need to add half an half or milk to your mashed taters to adjust the texture, do it in small increments. You can always add more if you need it but you can't take it out.

Step 2: Prep

Peeled taters will turn brown if left exposed to air. If you place them into a pot of cold water it will keep the potatoes from "rusting".

If you want you can put the pot directly onto the heat to start cooking. I will usually drain the water once all the peeling is done, and add fresh water. As you can see from the floating bit of peels in the picture I am not what you would call a "neat peeler". It is my cross to bear.

Step 3: Cook

Everyone has their own preference of how to cut up their taters to cook them. Some people quarter the spuds, others will cut them into bite size pieces. Personally I like to use my mandolin slicer set on thick slices so that every piece is the same thickness.

The finer you cut the potatoes the faster they cook, but that isn't always a good thing. I tried using the thin slice setting in the past but found it was too easy to overcook the potatoes resulting in potatoe mush. So now I use the thicker setting and I am very pleased with the results.

Step 4: Mix It All Together

Once the Potatoes are tender enough to be broken easily with a fork drain the water off and combine everything together.

Depending on how much sour cream you use will determine if you need to add half and half or not. With this batch I used about 8 oz of sour cream to 5 lbs of potatoes. Between the sour cream and the butter I did not need to add any half and half to make the mashed potatoes creamy.