Here is what I have found. If a bud isnt getting light it is almost a waste to leave it there. Usually you want to trim everythin off under the screen, but in your current run, since there is so much under the screen, I would say to get rid of all of the fan leaves under there that arent getting any light for better air flow. If the leaves arent getting light, it wont make a difference on how big the buds under the screen get. If you have to cut any branches or budsites off, cut the smallest(thinest) ones off first. The smaller the branch, the smaller the bud will be that it will produce, this is in regards to thickness not length. Otherwise making sure that all of the budsites up top get light(on the buds themselves and the fan leaves)always helps them hit their peak yield and keeping the food right. Nutrient burn hurts yield, that was my most common mistake in the begenning. It is a lot easier to fix a deficieny than a burn. Other than that, experiance is the next best thing for bigger harvests. Every grow I did got a little better than the one before it, so nomater how it turns out, pay attention to what you did wrongand when you did it and try not to repeat the problem. With all of that covered you are sure to have some fantastic harvests. And once again, great job on your first run so far.