I'd really be up for making small or mid-size tweaks to existing fantasy tracks like Deep Forest and Trial Mountain. Trial Mountain for example could easily have several layouts that retain the majority of the layout but tweak certain sections and really change the character of the track. One example could be taking out the first left/right in the counter clockwise version and replacing it with a relatively flat or slightly cambered large, fast sweeper into the left hander under the bridge. The left hander at the end of the long straight could easily be turned into a relatively tight, 1st or 2nd gear hairpin corner to really test the brakes. Take out the chicane at the top of the next hill and straighten the track to a 90 degree right hander, perhaps banked several degrees.
To me these are relatively simple changes that retain the majority of the work already done in creating the tracks but giving us what amounts to a nearly new track.