I am in love with boot socks.
Exhibit A: Knee-high socks topped with trim that peek out over the tops of your boots. Here is the tutorial to do your own from Laurel at Ducks in a Row. I made a black pair and a white pair to wear with my church skirts. LOVE them.
Exhibit B: Over the knee book socks. LOVE them over skinny jeans. I hit Target earlier this week and bought 3 sweaters on clearance for about $5 each, cut the arms off right where they meet the body of the sweater and serged along the raw edge. The sweater cuff becomes the top of your boot socks. I also cut the buttons off the sweater and stitched two to the outside of both socks.