One of the easiest methods to make fast skill points is to unlock skill songs in Forza Horizon 4. This can be done by purchasing the Huntsman’s Lodge for 750.000 credits.
This house comes with 3 free super wheel spins and the skill song perk. After this perk is unlocked, radio stations will play skill songs that increase your points gained and let your multiplier go up to 10.
Make sure to switch through all radio stations to find skill songs more frequently. This can be done by pressing right on the D-Pad.