When packing a tent, is it best to stuff it in its sack or roll/fold it? I always stuff my sleeping bag so I wasn't sure if it was the same for tents.
There are differing schools of thought on this:
Rolling/folding is a lot easier to manage in my opinion, easier to keep track of all the pieces, and when camping in dirty/snowy/wet environments makes it easier to keep the ground side of the tent together and the clean(ish) parts away from it.
Stuffing results in fewer creases in the fabric over extended periods of use, because you stuff it differently each time. This may make it less likely for the fabric to eventually wear out along a fold line. On the other hand, you're applying more stress to all the other parts of the tent.
I personally prefer folding my tent, but there isn't necessarily a "best" way. It depends on what's easier for you and what you think will be better for the long-term longevity of your gear.
There is the same discussion with paragliders getting porose due to packing methods. And there has been a lot of literature to that topic (a paraglider costs 3.000 USD after all), with a simple conclusion:
As nhinkle mentioned, the different methods result in different stress to the fabric. Usually your tent will get damaged due to constant stress on the same spot (e.g. folding line), not due to a high overall average wear. So I recommend to regullary change the packing method. Fold today, stuf tomorrow.
It is best to put everything away in the same order. the chance of the folds being along the same lines is very low. I find with modern tents the groundsheet wears out, (the very thin layer of waterproof that is on the woven nylon). I count the pegs and put them in the peg bag, the pole in the pole bag. The peg bag in the pole bag. Then fold the tent flat so the outside is outside. Make sure the strings are all in the right place (so that when opened the strings fall to the correct side) (There is one string that goes under my tent, if this ends up on the top it is not noticed until the tent is half up and then the tent has to be taken down again the pole removed, the string moved to the underside, then the pole put back in and the tent put up again.) Then roll the tent around the pole bag and put the lot in the tent bag.
(Stuffing a tent in a bag also means that it is harder to get in, it increases the volume, some parts of the tent will be under high compression.)
Putting stuff away in a fixed order means that pieces do not get lost. (This does not just apply to the tent)
Folding it up neatly means that you can put the tent up quickly in the dark when stealth camping. (Using the head torch to the minimum as this projects a beam of light like a lighthouse that can be seen from miles away) Also if you have to put the tent up in the rain the inside of the tent is protected from the rain. (I usually keep the inner and outer tent clipped together. But if I do separate them then the outer tent is wrapped around the inner tent. If it's raining the inner is tent put somewhere (eg in the rucksack) out of the rain, while the outer goes up.