These are usually pretty easy decisions for me based on how my roster is structured. For starters, I rarely carry more than 1 bench bat, so my lineup is essentially the same each day. My bench bat slots in at his position or UT whenever someone else has a day off or doesn't start, otherwise I roll with the same group. For SP it can be a bit trickier. I look at things like track record vs the specific team they're facing, the general offensive ability of the team they're facing, and I also check Vegas lines to see if they're favored, by how much, what the o/u on Total Runs for the game is, etc. If you're playing H2H, later in the week you also factor in how you're doing in the specific pitching categories (e.g. if you have a nice lead in K and W, you might sit a guy to avoid the possibility of him costing you ERA and WHIP if he gets blown up). It's an interesting dynamic, and you're going to frustrate yourself when you make the 'wrong' choice, but just keep pluggin away and good luck.