Slice the potatoes lengthwise, into even strips. Do not cut them into large cubes.
Make sure that everything that's going into the potatoes is warm, nothing cold.
When potatoes are done, be sure to drain them and then let them steam on the stove for a bit.
Mash the potatoes just until they are broken up. DO NOT OVER MASH!
Add in the warm liquid and use a whisk to gently stir.
Add butter!! Butter and potatoes belong together.
The more you mash and stir the potatoes the tougher/glue-ier they will become so make each mash and stir count!!
Use a rubber spatula to gently fold the potatoes if needed.