How do you guys do it?

This is right from the TCI website:

"Should I use an external transmission cooler in conjunction with the oil cooler supplied in the radiator?

Answer: Unless operating in an environment where the outside temperature is below 0°F, you should cap off the radiator cooler line openings and run your cooler lines directly to a new cooler mounted in front of the radiator. This allows the transmission to have its own cooling system and doesn't allow the engine water temperature to heat the fluid."