Avoid extra finishing work by weaving broken ends into the back of your stitches as you knit; this works best with stockinette and is shown in the video working the right side of stockinette, the yarn being woven into the wrong side.
This technique is locking the end yarn into every other stitch; see the locking in yarn tutorial page for photo + written tutorials for locking yarn into a stitch, if you prefer that instead of video, then do that with every other stitch, to weave it in across the stitches.
If you want to weave in two ends at the same time, lock one of them into every stitch, switching back and forth between the two strands on each stitch, and always bringing the new end up around the old end so that they are helping to lock each other into the knitting.
The video shows first for throwers (working yarn in right hand), then for pickers (working yarn in left hand).