I generally print first layer at 260/250 and the latter ones 10 degrees colder. I do the same with the build plate - starting with 90, and leaving it at 80 throughout the ret of the print. With some plates you have to bee mindful of PETG sticking too well (possibly damaging them) but it works out really well with PET/PEO plates, letting the print retain the texture of the build plate. On PEI I either print it cooler, or use glue (in this case it makes it easier to separate the print from the plate).