From what I've read, the key is time. An absolute or oil needs to sit in solution for as long as it takes to mix (which can be weeks, if I read correctly). I'm about to find out, as I have oakmoss absolute and fractionated coconut oil with my latest scent experiment.
Edit: or not, as the oakmoss mixed easily.
Edit 2: The waxier substances are apparently the more difficult to mix w/FCO... I've also read that mixing these with some EO can help.