Another ridiculously easy stitch that produces a pleasant result, the V treble (US: double) crochet stitch is literally just two trebles in a single stitch and then skip one. It seriously couldn’t get simpler.
In my photo, though, you can see that the first few rows I just did back and forth in brown. But you really don’t see the V pattern clearly unless you use different colours, so I put in a pink row and, as you can see beneath the first pink row, I tried to carry the yarn along the row so that it was available at the other end to come back. I don’t think that looks particularly good, though. One could start the second colour at the beginning of the previous row, instead of the end, so that you then carry the brown yarn up for the return row, and do the same with the pink for next return row. That would probably be better than constantly having to tie off ends.
Still, this is a very simple but effective stitch and I can imagine doing a jumper with a couple of stripes around the bottom!