Manual crossing is my favourite thing in the game

.
I would suggest using a camera like Dynamic Wide which maintains the same angle wherever you are on the pitch. It may look nice to play on Stadium or Broadcast cameras, but they are a nightmare to perform manual crosses on.
If you think you are putting too much power on it, try holding R2 when you cross. This is for a higher lofted cross, but if you only use around half power then it won't lift the ball up too high but will still take a lot of the pace off, useful for an early ball in behind the defence. This is one I did online;
Chipped through ball can also be used quite effectively as a slower cross as well, especially when you just want to stand one up from the byline for a header rather than flashing it across with pace.
And finally, get to know who on your team has the "Pinpoint Crossing" skill. It dramatically changes the way that player crosses the ball... Far more pace and curl on the ball; it can be deadly when you use it well, but also really annoying if you forget and don't compensate for it in your aim. Holding R2 with these players is preferable in many situations to take some of that pace off.