I've got several tarps, especially those nasty, crinkly, hard to pack poly monstrosities, but my two main ones are a homemade silnylon 12x12 that weighs less than a pound and crushes down to the size of a baseball, and my homemade coated polyester 10x10 that's about 2 1/2lbs and takes up the room of 2 Nalgenes. the poly tarps are only used for car camping as backups, or if I'm leading a large youth group where more square footage or a windbreak are desirable
both my lightweight tarps have loops about every 2' around the perimeter, a center loop on both sides, and 4 more on the diagonal halfway between the centre and corners, I don't really have a standard setup, every setup is done to make the best use of the terrain and conditions- for instance in really windy, rainy conditions I generally rig like a lean-to with added guys to the midpoint and/or center loops to pull out the middle to make for more useable space while still keeping the ends lower to protect better from sidewinds.
for fair weather I'll usually suspend it under the ridgeline in a diamond pattern for cooking, using the loops on the diagonal and either tautlines or prussics- this lets me slide or adjust the tarp on the fly- pull loose the 2 end loops and I can easily slide the tarp to one end out of the way in seconds on nice days, or pull it tight quickly if the weather turns bad. If I'm using both tarps I usually run them end to end in a lean-to configuration.