Make sure that the rope is the minimum length
When using Dyneema you want some excess length that allows you to cut of a bit at the top every now and then, as Colin explained earlier, to keep ahead of wear at the sheaves and cleat.
To avoid tangles I throw the halyard in a bailer bucket that is stuck between the mast and the forward tank. I throw it in as it comes down, in my experience it is the neat coiling that causes tangling. If you throw it in as it comes down it should go up as it came down IMHO. I am quite satisfied with this solution but maybe someone can engineer a system with blocks and bungee, for those suffering from neatness compulsion, to take up the halyard below the floor boards ?