I generally play with mast rake only if I expect extreme condition-either way. If it's going to be very windy, I'll send the mast back a little. If I know it'll be light for an entire day, I'll send it forward a little. It's important to know where the baseline is.

Also, do keep in mind that changing rake will effect things such as spinnaker luff tension. I'm a stickler on proper spin luff tension and have to be aware that when I change the rake, the tension will have to be adjusted accordingly via the spin pole or up top with the bale setting.