I'm new and just getting into carbon fiber work. I did my first mold and ended up with little success. My carbon fiber ended up gluing to my mold. This time i put 4 heavy coats of pva release agent to try and avoid this. What I really want to find out is making split moulds. Many of the parts i want to produce carbon fiber copies of have plastic parts on the back. Was thinking of 3d printing these and gluing them on or a split mold of some sort. any advice is welcomed.

Not certain just what process that you are using to make the part (hand lay-up/vac bagging etc.) but using separate pieces of fabric for small sections where there's a change in contour can help with ensuring the fabric conforms better to the shape. A bit ofspray tack and a roller cutter can help you get neat cut lines and help with overall appearance of the finished parts. If working with a single piece of fabric, though, work from the centre outwards when laying the fabric in to help make sure that it doesn't bridge around tricky areas.