@FullDuplex your last comment leads me to my next sort of tip that I feel a lot of people over look especially newer growers. I remember reading and following my bottled nutrient schedule to a T. Reading plants is important and understanding that these schedules are very basic. They also do NOT work well for autoflowers at all.
One thing I do that I learned the hard way with many thanks to
@Jupiter was when to switch to the bloom nutrients which are higher in PK. I used to start adding bloom nutrients to my plants when I first saw signs of preflowers. With advice I listened and waited till the stretch fully stopped.
If given to early the plants will start to flower. If it's delayed till the stretch stops the plant will continue to grow till they reach their max potential. People often ask how the hell I managed 6 1/2 foot tall autos and that's how. Shortly after they stop stretching I do 2 transition feeds and right into full flower nutrients. 1-3 weeks later start hitting them hard with magnesium and a 0-10-10 formula. Great solid buds on huge plants.