May I also add when tying down a tarp, unless it is one of those heavy old canvass tarps, I have always felt most people are doing it wrong. Allow me to explain...
When you tie from the ringlets in a high wind (and I don't mean tornado, just decent gusts) you risk the ringlets just ripping loose from the tarp altogether.
What I suggest
550 paracord is cheap and strong. Run a length of rope through a ringlet, across the tarp and then threaded through the ringlet across from it. I create a sort of rib cage with the rope across the tarp threaded through the ringlets and then tied down. This way the tarp goes all the way to the ground (long tarp not square) and the loops of the rope are connected to a small handful of metal tent stakes I keep with me. This prevents rips and tears and makes your cover much stronger, and less noisy in the wind.
Also, if I may:
When tying off a ridgeline such as in the photo I see one more mistake. Notice the rope is wrapped forever around each tree in an attempt to keep it taught and strong? Problem is there is a single strand of rope.
Best method is to run several strand across between the two trees for your ridgeline, use less to tie it on either side. You don't need a ton of rope wrapped around each tree, just a couple of good knots. Running several strands across rather than just one is what will strengthen the ridgeline, this is basic engineering. This also has the added advantage of more hang points and side by side which is great for running some bug netting around you inside and underneath your tarp.