3. I would also suggest turning off apps that take up space on the tablet. I only use my samsung tab for the phantom and internet browsing so i basically turned off all of the apps.
4. download Zapper Task Killer and kill any open running apps before opening up the dji go app every time, this will free up ram. (I have no lag after doing this step)
This sounds like a lot to go through but after doing steps 1-3, you wont ever have to do it again. Step 4 is the only thing you would have to do before each flight.