I would think both, more the 1 way to skin a cat lol. Experiment with it, my 1st grow I accidentally topped just before flower. Way later than I would top on purpose, but worked out good. You can top after whatever just mak sure she has enough veg left. Days 14-20 are optimal but not set in stone, some strains veg longer so you could do later. Lst as long as you're not cutting the branch with string, yarn, etc something that's sharp you'll be ok not sure you can mess up. I use soft rubber ties, best thing I've found. Jump on YouTube and watch as much as you can, you will be able to sort out the bad techniques after you see a few. Stay lifted.