There's really no wrong way to use a margarita pool
"What is best in Life? To crush your enemies, to see them driven before you, and to hear the lamentations of their women."
Yes, you can use two different tech cards to manipulate the same die twice.
Couldn't a die be manipulated 1 time for each different alien tech card in your possession? I can think of 4 different cards that allow die manipulation.