Crossing your best females is ALWAYS FUN....crossing with strains with VERY SPECIFIC traits (like bluberry) is hard unless you have the original donors.....
My best plant EVER, was a AK47 reversal put into a special Silver Pearl....It had less than a 100% stretch and stayed under 2.5ft, BUT would carry 6 oz on a prunned plant with 6 tops.....I grew it for close to 7 yrs, cause it was better than both the AK47 and the Silver Pearl parents....if your just looking for something different and you cross a cpl of your best plants, you most likely will find a keeper or two....never know, you may find the next great strain....it might be easy to stablize too...there are quite of few famous strains that were not 'engineered' by breeders, but were just phenotypes of common strains that had special traits...There are even a cpl that evolved from found BAG SEEDS...the original Gorilla glue was an accidental hermaphrodite pollination from Sour D and I think a Chem dawg...So, you never know what a cpl good female can produce!!!!...YT