Can you spot the difference???
When you braid, every single braid you do should look the same in size, length and tension. When you practice braiding, sizing each braid and learning to do so is highly important.
I always say to trim the braids. I do this because I know the difference. You are supposed to trim the spiky bits off the braids after you've completed the clients style. A-lot of braiders don't do this because it adds extra time to the booking. But as the picture above shows with the red braids. Your braids will look so much better if you do it, plus they will age better.
If you want to go the extra mile, then snip off the very ends of the braids, don't leave them looking scraggly. The picture on the right will help you see that difference. If you want to be the best you can be at braiding, you go the extra mile while the others don't. This will propel you straight ahead and your clientele will appreciate this and keep coming back. This is from experience :)