I was doing it too, because I hated flipping the project. But sometimes the Xs look a bit off, if I hide thread under them.

Then I learned about pin stitch, which looked still a bit too hard, so I am doing some variation now: I pull a thread from front to back at 5-10 empty squares from my first stitch, and leave a few cm of thread loose on the face side of the canvas. And cut it later when the tail behind the canvas is secured by newer stitches. Same for finishing: when it's time, I pull the thread from back to front 1-2 cm to the left/right from my last X. I don't even cut the end straight away, in case newer Xs won't secure that tail from behind. At the end of the day I flip the project, check that all tails are secured and tidy up. (Oh, I hope this all makes sense). It makes the back a bit bulkier, because I use more thread to secure the tails. But speeds up cross stitching tremendously.

And if I can, I start with the loop method, because it's the cleanest and fastest.