Staying on top of problems
Dealing with problems in veg doesn’t really cause me much stress anymore because I currently only grow photoperiods, and that means I have all the time and room I need to get my plant back into shape. I could basically remove all the leaves and as long as the plant doesn’t die from it they will all grow back. You don’t get this in flowering. Once you’ve made the light on/off switch your plants go on a timer. So whenever you see a new issue, you need to be diligent and figure out how to fix it.
You will see yellow leaves and probably will pull more than a few dead leaves off in flowering. It’s really very common for that to happen the further you get into flowering. It’s fall after all, that what leaves do. The combination of low nitrogen (which you don’t want a lot of in flowering) combined with a lack of light penetration makes those bottom leaves susceptible to yellowing and dying, and that is completely fine. If you see that in veg there is an issue, and if you see the yellowing/dying leaves move up the plant in flowering then there is most likely an issue as well.
Make sure to look at other growers plants when they are in different stages. Again, as long as you properly handle plant issues and have leaves on your plant then the buds will come. Every time I see a cannabis plant on the news, grown by a friend, on websites that sell seeds, etc. they are never perfect. I see nute burn, too dark of leaves, worrisome red stems, yellowing, etc.