8×10 flat tarp tie-out question

I like them pretty much centered. However, you could do centered on one side and about 1/3 on the other side. You will find it rare that you need 4 anyway. Set up as a lean-to, you will find that the 1/3 point works better as a center support.

For example, off the ground, 1/3 will give you a bit more space inside. When over a table (with 4′ guy-lines,) the 1/3 point works pretty well propped with a hiking staff.

In windy weather using an A-frame, you will find that the 1/4 points do better holding things down (half way on a side.) I would split the difference and just face the 1/4 point into the wind rather than either of the ends…

Or, do both. For an extra ounce in weight, you can have both sets.

One centred in each panel plus another 4 at the quarter points.