For mashed potatoes: I use russett or yukon gold. I add heavy cream, butter, sour cream, salt and pepper.
For roasted garlic mashed potatoes I take a whole head of garlic, cut it in half, pour extra virgin olive oil over both halves, wrap them in tin foil, and roast them in a 400 degree oven while the potatoes cook. I then squeeze the garlic into the potatoes and mash the garlic along with the potatoes.
IMHO the key to good scrambled eggs is to add a tablespoon of milk for every 2 eggs and cook the eggs over low heat. This will make them soft and fluffy.