The formula’s for PoI are in the white paper. https://drive.google.com/drive/u/1/folders/0B_0Z9jDGHPxPfjRiNWJzLWl1aHZ6MEF1eXpSR0lSQ05JTzVqUEU5S2tyY2ZOSzMxZkdQd0U
There must be a way to optimize blocks as it is determined by math, but at the same time how other people interact in the network can then affect your PoI too as it is a zero-sum game. If you are making your harvesting going up, then mine or somebody else’s will go down.
One thing that you can do is try to get your account in a cluster, and the easiest way to do that is to interact with an exchange I guess. I think that can maybe give you up to a 10% boost I think. Form looking at the formula, that is the one thing I can get out of it pretty easily.
I have also experimented with splitting accounts and it seems that my smaller accounts do a little better per weight than my larger accounts, but then again, maybe they were in better clusters or did something else differently. Not sure.