Depending on what you are using for backing, I'd be more inclined to leave long tails, knot them and bury them. I've started doing that more as the backstitching sometimes becomes very noticeable on the back side. Often it's hidden in a seam or the color blends well on the front, but this does not happen on the back.
I do mine on a LA. I pull and knot as I am going, so I don't have a lot of loose strings getting in my way, and a boat load of threads to knot and bury after the quilt is off the frame. I keep a needle with a larger eye stuck to the LA so I can easily do that. It does get a bit tedious when you have an 18" block with a lot of small sections that don't interconnect and you are switching between three thread colors - I only did one color at a time, but I had 5-10 sections of each color with knots at the start and end of each. The plus side, it looks as nice on the back as it does on the front. this quilt is now displayed at my LQS, so I knew I wanted to be very particular.
If I am making a quilt were I'm not near as concerned about how it looks on the back, or if the backing will easily hide the stitching, I'll backstitch and trim threads instead of going to the work of knotting and burying.